diff --git a/lib/src/command/add.dart b/lib/src/command/add.dart
index 31d4a1159..49352e791 100644
--- a/lib/src/command/add.dart
+++ b/lib/src/command/add.dart
@@ -117,6 +117,11 @@ For example (follow the same format including spaces):
       help: 'Path of git package in repository',
       hide: true,
     );
+    argParser.addOption(
+      'git-tag-pattern',
+      help: 'The tag-pattern to search for versions in repository',
+      hide: true,
+    );
     argParser.addOption(
       'hosted-url',
       help: 'URL of package host server',
@@ -275,7 +280,9 @@ Specify multiple sdk packages with descriptors.''');
             location: Uri.parse(entrypoint.workPackage.pubspecPath),
             overridesFileContents: overridesFileContents,
             overridesLocation: Uri.file(overridesPath),
-            containingDescription: RootDescription(entrypoint.workPackage.dir),
+            containingDescription: ResolvedRootDescription.fromDir(
+              entrypoint.workPackage.dir,
+            ),
           ),
         )
         .acquireDependencies(
@@ -541,6 +548,11 @@ Specify multiple sdk packages with descriptors.''');
       if (gitUrl == null) {
         usageException('The `--git-url` is required for git dependencies.');
       }
+      if (argResults.gitRef != null && argResults.tagPattern != null) {
+        usageException(
+          'Cannot provide both `--git-ref` and `--git-tag-pattern`.',
+        );
+      }
 
       /// Process the git options to return the simplest representation to be
       /// added to the pubspec.
@@ -552,6 +564,7 @@ Specify multiple sdk packages with descriptors.''');
             containingDir: p.current,
             ref: argResults.gitRef,
             path: argResults.gitPath,
+            tagPattern: argResults.tagPattern,
           ),
         );
       } on FormatException catch (e) {
@@ -566,7 +579,7 @@ Specify multiple sdk packages with descriptors.''');
       ref = cache.sdk.parseRef(
         packageName,
         argResults.sdk,
-        containingDescription: RootDescription(p.current),
+        containingDescription: ResolvedRootDescription.fromDir(p.current),
       );
     } else {
       ref = PackageRef(
@@ -652,7 +665,7 @@ Specify multiple sdk packages with descriptors.''');
             cache.sources,
             // Resolve relative paths relative to current, not where the
             // pubspec.yaml is.
-            containingDescription: RootDescription(p.current),
+            containingDescription: ResolvedRootDescription.fromDir(p.current),
           );
         } on FormatException catch (e) {
           usageException('Failed parsing package specification: ${e.message}');
@@ -787,6 +800,8 @@ extension on ArgResults {
   bool get isDryRun => flag('dry-run');
   String? get gitUrl => this['git-url'] as String?;
   String? get gitPath => this['git-path'] as String?;
+  String? get tagPattern => this['git-tag-pattern'] as String?;
+
   String? get gitRef => this['git-ref'] as String?;
   String? get hostedUrl => this['hosted-url'] as String?;
   String? get path => this['path'] as String?;
diff --git a/lib/src/command/dependency_services.dart b/lib/src/command/dependency_services.dart
index fddbb1c33..9b8c63acb 100644
--- a/lib/src/command/dependency_services.dart
+++ b/lib/src/command/dependency_services.dart
@@ -424,6 +424,7 @@ class DependencyServicesApplyCommand extends PubCommand {
         } else if (targetRevision != null &&
             (lockFileYaml['packages'] as Map).containsKey(targetPackage)) {
           final ref = entrypoint.lockFile.packages[targetPackage]!.toRef();
+
           final currentDescription = ref.description as GitDescription;
           final updatedRef = PackageRef(
             targetPackage,
@@ -432,6 +433,7 @@ class DependencyServicesApplyCommand extends PubCommand {
               path: currentDescription.path,
               ref: targetRevision,
               containingDir: directory,
+              tagPattern: currentDescription.tagPattern,
             ),
           );
           final versions = await cache.getVersions(updatedRef);
@@ -480,7 +482,9 @@ class DependencyServicesApplyCommand extends PubCommand {
           updatedPubspecs[package.dir].toString(),
           cache.sources,
           location: toUri(package.pubspecPath),
-          containingDescription: RootDescription(package.dir),
+          containingDescription: ResolvedRootDescription(
+            RootDescription(package.dir),
+          ),
         ),
       );
       // Resolve versions, this will update transitive dependencies that were
diff --git a/lib/src/command/lish.dart b/lib/src/command/lish.dart
index 804287aab..a2d405f87 100644
--- a/lib/src/command/lish.dart
+++ b/lib/src/command/lish.dart
@@ -395,7 +395,9 @@ the \$PUB_HOSTED_URL environment variable.''');
           ),
         ),
         cache.sources,
-        containingDescription: RootDescription(p.dirname(archive)),
+        containingDescription: ResolvedRootDescription.fromDir(
+          p.dirname(archive),
+        ),
       );
     } on FormatException catch (e) {
       dataError('Failed to read pubspec.yaml from archive: ${e.message}');
diff --git a/lib/src/command/unpack.dart b/lib/src/command/unpack.dart
index 21d096be9..98821205a 100644
--- a/lib/src/command/unpack.dart
+++ b/lib/src/command/unpack.dart
@@ -144,7 +144,9 @@ in a directory `foo-<version>`.
         final pubspec = Pubspec.load(
           destinationDir,
           cache.sources,
-          containingDescription: RootDescription(destinationDir),
+          containingDescription: ResolvedRootDescription.fromDir(
+            destinationDir,
+          ),
         );
         final buffer = StringBuffer();
         if (pubspec.resolution != Resolution.none) {
@@ -212,7 +214,7 @@ Creating `pubspec_overrides.yaml` to resolve it without those overrides.''');
           // Resolve relative paths relative to current, not where the
           // pubspec.yaml is.
           location: p.toUri(p.join(p.current, 'descriptor')),
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
       } on FormatException catch (e) {
         usageException('Failed parsing package specification: ${e.message}');
diff --git a/lib/src/command/upgrade.dart b/lib/src/command/upgrade.dart
index 5626dde41..9d4ba459a 100644
--- a/lib/src/command/upgrade.dart
+++ b/lib/src/command/upgrade.dart
@@ -17,7 +17,6 @@ import '../package_name.dart';
 import '../pubspec.dart';
 import '../pubspec_utils.dart';
 import '../solver.dart';
-import '../source/hosted.dart';
 import '../utils.dart';
 
 /// Handles the `upgrade` pub command.
@@ -248,11 +247,11 @@ be direct 'dependencies' or 'dev_dependencies', following packages are not:
     // Mapping from original to changed value.
     var changes = <Package, Map<PackageRange, PackageRange>>{};
     for (final package in entrypoint.workspaceRoot.transitiveWorkspace) {
-      final declaredHostedDependencies = [
+      final declaredUpgradableDependencies = [
         ...package.dependencies.values,
         ...package.devDependencies.values,
-      ].where((dep) => dep.source is HostedSource);
-      for (final dep in declaredHostedDependencies) {
+      ].where((dep) => dep.description.hasMultipleVersions);
+      for (final dep in declaredUpgradableDependencies) {
         final resolvedPackage = resolvedPackages[dep.name]!;
         if (!toUpgrade.contains(dep.name)) {
           // If we're not trying to upgrade this package, or it wasn't in the
diff --git a/lib/src/entrypoint.dart b/lib/src/entrypoint.dart
index 36719a185..de21237e5 100644
--- a/lib/src/entrypoint.dart
+++ b/lib/src/entrypoint.dart
@@ -97,7 +97,7 @@ class Entrypoint {
         pubspec = Pubspec.load(
           dir,
           cache.sources,
-          containingDescription: RootDescription(dir),
+          containingDescription: ResolvedRootDescription.fromDir(dir),
           allowOverridesFile: true,
         );
       } on FileException {
@@ -116,7 +116,9 @@ class Entrypoint {
                     cache.sources,
                     expectedName: expectedName,
                     allowOverridesFile: withPubspecOverrides,
-                    containingDescription: RootDescription(path),
+                    containingDescription: ResolvedRootDescription.fromDir(
+                      path,
+                    ),
                   ),
           withPubspecOverrides: true,
         );
diff --git a/lib/src/global_packages.dart b/lib/src/global_packages.dart
index 2d4eae346..880c7f9ee 100644
--- a/lib/src/global_packages.dart
+++ b/lib/src/global_packages.dart
@@ -93,6 +93,7 @@ class GlobalPackages {
     required bool overwriteBinStubs,
     String? path,
     String? ref,
+    String? tagPattern,
   }) async {
     final name = await cache.git.getPackageNameFromRepo(
       repo,
@@ -100,6 +101,7 @@ class GlobalPackages {
       path,
       cache,
       relativeTo: p.current,
+      tagPattern: tagPattern,
     );
 
     // TODO(nweiz): Add some special handling for git repos that contain path
@@ -115,7 +117,7 @@ class GlobalPackages {
           if (path != null) 'path': path,
           if (ref != null) 'ref': ref,
         },
-        containingDescription: RootDescription(p.current),
+        containingDescription: ResolvedRootDescription.fromDir(p.current),
         languageVersion: LanguageVersion.fromVersion(sdk.version),
       );
     } on FormatException catch (e) {
diff --git a/lib/src/language_version.dart b/lib/src/language_version.dart
index 6bf4c8adf..fdfb2bfb5 100644
--- a/lib/src/language_version.dart
+++ b/lib/src/language_version.dart
@@ -65,6 +65,8 @@ class LanguageVersion implements Comparable<LanguageVersion> {
 
   bool get supportsWorkspaces => this >= firstVersionWithWorkspaces;
 
+  bool get supportsTagPattern => this >= firstVersionWithTagPattern;
+
   bool get forbidsUnknownDescriptionKeys =>
       this >= firstVersionForbidingUnknownDescriptionKeys;
 
@@ -105,6 +107,7 @@ class LanguageVersion implements Comparable<LanguageVersion> {
   static const firstVersionWithNullSafety = LanguageVersion(2, 12);
   static const firstVersionWithShorterHostedSyntax = LanguageVersion(2, 15);
   static const firstVersionWithWorkspaces = LanguageVersion(3, 5);
+  static const firstVersionWithTagPattern = LanguageVersion(3, 9);
   static const firstVersionForbidingUnknownDescriptionKeys = LanguageVersion(
     3,
     7,
diff --git a/lib/src/package_name.dart b/lib/src/package_name.dart
index 647561ed0..7ec1c285e 100644
--- a/lib/src/package_name.dart
+++ b/lib/src/package_name.dart
@@ -174,7 +174,7 @@ class PackageRange {
   bool get _showVersionConstraint {
     if (isRoot) return false;
     if (!constraint.isAny) return true;
-    return description.source.hasMultipleVersions;
+    return description.hasMultipleVersions;
   }
 
   /// Returns a copy of `this` with the same semantics, but with a `^`-style
diff --git a/lib/src/pubspec.dart b/lib/src/pubspec.dart
index 0923ba74d..5ebc55fa1 100644
--- a/lib/src/pubspec.dart
+++ b/lib/src/pubspec.dart
@@ -61,7 +61,7 @@ class Pubspec extends PubspecBase {
 
   /// It is used to resolve relative paths. And to resolve path-descriptions
   /// from a git dependency as git-descriptions.
-  final Description _containingDescription;
+  final ResolvedDescription _containingDescription;
 
   /// Directories of packages that should resolve together with this package.
   late List<String> workspace = () {
@@ -279,7 +279,7 @@ environment:
     SourceRegistry sources, {
     String? expectedName,
     bool allowOverridesFile = false,
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
   }) {
     final pubspecPath = p.join(packageDir, pubspecYamlFilename);
     final overridesPath = p.join(packageDir, pubspecOverridesFilename);
@@ -324,7 +324,7 @@ environment:
       sources,
       expectedName: expectedName,
       allowOverridesFile: withPubspecOverrides,
-      containingDescription: RootDescription(dir),
+      containingDescription: ResolvedRootDescription.fromDir(dir),
     );
   }
 
@@ -362,7 +362,7 @@ environment:
        _overridesFileFields = null,
        // This is a dummy value. Dependencies should already be resolved, so we
        // never need to do relative resolutions.
-       _containingDescription = RootDescription('.'),
+       _containingDescription = ResolvedRootDescription.fromDir('.'),
        super(
          fields == null ? YamlMap() : YamlMap.wrap(fields),
          name: name,
@@ -382,7 +382,7 @@ environment:
     YamlMap? overridesFields,
     String? expectedName,
     Uri? location,
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
   }) : _overridesFileFields = overridesFields,
        _includeDefaultSdkConstraint = true,
        _givenSdkConstraints = null,
@@ -432,7 +432,7 @@ environment:
     Uri? location,
     String? overridesFileContents,
     Uri? overridesLocation,
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
   }) {
     final YamlMap pubspecMap;
     YamlMap? overridesFileMap;
@@ -576,7 +576,7 @@ Map<String, PackageRange> _parseDependencies(
   SourceRegistry sources,
   LanguageVersion languageVersion,
   String? packageName,
-  Description containingDescription, {
+  ResolvedDescription containingDescription, {
   _FileType fileType = _FileType.pubspec,
 }) {
   final dependencies = <String, PackageRange>{};
diff --git a/lib/src/solver/version_solver.dart b/lib/src/solver/version_solver.dart
index 165da9b19..0d0f119e7 100644
--- a/lib/src/solver/version_solver.dart
+++ b/lib/src/solver/version_solver.dart
@@ -586,7 +586,10 @@ class VersionSolver {
     // can't be downgraded.
     if (_type == SolveType.downgrade) {
       final locked = _lockFile.packages[package];
-      if (locked != null && !locked.source.hasMultipleVersions) return locked;
+      if (locked != null &&
+          !locked.description.description.hasMultipleVersions) {
+        return locked;
+      }
     }
 
     if (_unlock.isEmpty || _unlock.contains(package)) return null;
diff --git a/lib/src/source.dart b/lib/src/source.dart
index 0c3fe70cc..37727e5b7 100644
--- a/lib/src/source.dart
+++ b/lib/src/source.dart
@@ -51,12 +51,6 @@ abstract class Source {
   /// all sources.
   String get name;
 
-  /// Whether this source can choose between multiple versions of the same
-  /// package during version solving.
-  ///
-  /// Defaults to `false`.
-  bool get hasMultipleVersions => false;
-
   /// Parses a [PackageRef] from a name and a user-provided [description].
   ///
   /// When a [Pubspec] is parsed, it reads in the description for each
@@ -81,7 +75,7 @@ abstract class Source {
   PackageRef parseRef(
     String name,
     Object? description, {
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
     required LanguageVersion languageVersion,
   });
 
@@ -190,6 +184,11 @@ abstract class Source {
 /// with a version constraint.
 abstract class Description {
   Source get source;
+
+  /// Whether the source can choose between multiple versions of this
+  /// package during version solving.
+  bool get hasMultipleVersions;
+
   Object? serializeForPubspec({
     required String? containingDir,
     required LanguageVersion languageVersion,
diff --git a/lib/src/source/cached.dart b/lib/src/source/cached.dart
index 86dbc0a18..2cfa2a1ff 100644
--- a/lib/src/source/cached.dart
+++ b/lib/src/source/cached.dart
@@ -32,7 +32,7 @@ abstract class CachedSource extends Source {
         packageDir,
         cache.sources,
         expectedName: id.name,
-        containingDescription: id.description.description,
+        containingDescription: id.description,
       );
     }
 
diff --git a/lib/src/source/git.dart b/lib/src/source/git.dart
index 7bed62f63..af104f390 100644
--- a/lib/src/source/git.dart
+++ b/lib/src/source/git.dart
@@ -24,6 +24,8 @@ import 'cached.dart';
 import 'path.dart';
 import 'root.dart';
 
+typedef TaggedVersion = ({Version version, String commitId});
+
 /// A package source that gets packages from Git repos.
 class GitSource extends CachedSource {
   static GitSource instance = GitSource._();
@@ -37,12 +39,13 @@ class GitSource extends CachedSource {
   PackageRef parseRef(
     String name,
     Object? description, {
-    Description? containingDescription,
+    ResolvedDescription? containingDescription,
     required LanguageVersion languageVersion,
   }) {
     String url;
     String? ref;
     String? path;
+    String? tagPattern;
     if (description is String) {
       url = description;
     } else if (description is! Map) {
@@ -77,16 +80,42 @@ class GitSource extends CachedSource {
       }
       path = descriptionPath;
 
+      // TODO: can we avoid relying on key presence?
+      if (description.containsKey('tag_pattern')) {
+        if (!languageVersion.supportsTagPattern) {
+          throw FormatException(
+            'Using `git: {tagPattern: }` is only supported with a minimum SDK '
+            'constraint of ${LanguageVersion.firstVersionWithTagPattern}.',
+          );
+        }
+        switch (description['tag_pattern']) {
+          case final String descriptionTagPattern:
+            tagPattern = descriptionTagPattern;
+            // Do an early compilation to validate the format.
+            compileTagPattern(tagPattern);
+          default:
+            throw const FormatException(
+              "The 'tag_pattern' field of the description "
+              'must be a string or null.',
+            );
+        }
+      }
+
+      if (ref != null && tagPattern != null) {
+        throw const FormatException(
+          'A git description cannot have both a ref and a `tag_pattern`.',
+        );
+      }
       if (languageVersion.forbidsUnknownDescriptionKeys) {
         for (final key in description.keys) {
-          if (!['url', 'ref', 'path'].contains(key)) {
+          if (!['url', 'ref', 'path', 'tag_pattern'].contains(key)) {
             throw FormatException('Unknown key "$key" in description.');
           }
         }
       }
     }
 
-    final containingDir = switch (containingDescription) {
+    final containingDir = switch (containingDescription?.description) {
       RootDescription(path: final path) => path,
       PathDescription(path: final path) => path,
       _ => null,
@@ -99,6 +128,7 @@ class GitSource extends CachedSource {
         containingDir: containingDir,
         ref: ref,
         path: _validatedPath(path),
+        tagPattern: tagPattern,
       ),
     );
   }
@@ -140,6 +170,15 @@ class GitSource extends CachedSource {
         'must be a string.',
       );
     }
+
+    final tagPattern = description['tag_pattern'];
+    if (tagPattern is! String?) {
+      throw const FormatException(
+        "The 'tag_pattern' field of the description "
+        'must be a string.',
+      );
+    }
+
     return PackageId(
       name,
       version,
@@ -149,6 +188,7 @@ class GitSource extends CachedSource {
           ref: ref,
           path: _validatedPath(description['path']),
           containingDir: containingDir,
+          tagPattern: tagPattern,
         ),
         resolvedRef,
       ),
@@ -251,23 +291,35 @@ class GitSource extends CachedSource {
     String? path,
     SystemCache cache, {
     required String relativeTo,
+    required String? tagPattern,
   }) async {
+    if (ref != null && tagPattern != null) {
+      fail('Cannot have both a `tagPattern` and a `ref`');
+    }
     final description = GitDescription(
       url: url,
       ref: ref,
       path: path,
       containingDir: relativeTo,
+      tagPattern: tagPattern, // TODO
     );
     return await _pool.withResource(() async {
       await _ensureRepoCache(description, cache);
       final path = _repoCachePath(description, cache);
-      final revision = await _firstRevision(path, description.ref);
+
+      final revision =
+          tagPattern != null
+              ? (await _listTaggedVersions(
+                path,
+                compileTagPattern(tagPattern),
+              )).last.commitId
+              : await _firstRevision(path, description.ref);
       final resolvedDescription = ResolvedGitDescription(description, revision);
 
       return Pubspec.parse(
         await _showFileAtRevision(resolvedDescription, 'pubspec.yaml', cache),
         cache.sources,
-        containingDescription: description,
+        containingDescription: resolvedDescription,
       ).name;
     });
   }
@@ -322,32 +374,68 @@ class GitSource extends CachedSource {
     return await _pool.withResource(() async {
       await _ensureRepoCache(description, cache);
       final path = _repoCachePath(description, cache);
-      final revision = await _firstRevision(path, description.ref);
-      final pubspec = await _describeUncached(ref, revision, cache);
-
-      return [
-        PackageId(
-          ref.name,
-          pubspec.version,
-          ResolvedGitDescription(description, revision),
-        ),
-      ];
+      final result = <PackageId>[];
+      if (description.tagPattern case final String tagPattern) {
+        final versions = await _listTaggedVersions(
+          path,
+          compileTagPattern(tagPattern),
+        );
+        for (final version in versions) {
+          result.add(
+            PackageId(
+              ref.name,
+              version.version,
+              ResolvedGitDescription(description, version.commitId),
+            ),
+          );
+        }
+        return result;
+      } else {
+        final revision = await _firstRevision(path, description.ref);
+
+        final Pubspec pubspec;
+        pubspec = await _describeUncached(ref, revision, cache);
+        result.add(
+          PackageId(
+            ref.name,
+            pubspec.version,
+            ResolvedGitDescription(description, revision),
+          ),
+        );
+        return [
+          PackageId(
+            ref.name,
+            pubspec.version,
+            ResolvedGitDescription(description, revision),
+          ),
+        ];
+      }
     });
   }
 
   /// Since we don't have an easy way to read from a remote Git repo, this
   /// just installs [id] into the system cache, then describes it from there.
   @override
-  Future<Pubspec> describeUncached(PackageId id, SystemCache cache) {
+  Future<Pubspec> describeUncached(PackageId id, SystemCache cache) async {
     final description = id.description;
     if (description is! ResolvedGitDescription) {
       throw StateError('Called with wrong ref');
     }
-    return _pool.withResource(
+    final pubspec = await _pool.withResource(
       () => _describeUncached(id.toRef(), description.resolvedRef, cache),
     );
+    if (pubspec.version != id.version) {
+      throw PackageNotFoundException(
+        'Expected ${id.name} version ${id.version} '
+        'at commit ${description.resolvedRef}, '
+        'found ${pubspec.version}.',
+      );
+    }
+    return pubspec;
   }
 
+  final Map<(PackageRef, String), Pubspec> _pubspecAtRevisionCache = {};
+
   /// Like [describeUncached], but takes a separate [ref] and Git [revision]
   /// rather than a single ID.
   Future<Pubspec> _describeUncached(
@@ -359,18 +447,16 @@ class GitSource extends CachedSource {
     if (description is! GitDescription) {
       throw ArgumentError('Wrong source');
     }
-    await _ensureRevision(description, revision, cache);
-
-    return Pubspec.parse(
-      await _showFileAtRevision(
-        ResolvedGitDescription(description, revision),
-        'pubspec.yaml',
-        cache,
-      ),
-      cache.sources,
-      expectedName: ref.name,
-      containingDescription: ref.description,
-    );
+    return _pubspecAtRevisionCache[(ref, revision)] ??= await () async {
+      await _ensureRevision(description, revision, cache);
+      final resolvedDescription = ResolvedGitDescription(description, revision);
+      return Pubspec.parse(
+        await _showFileAtRevision(resolvedDescription, 'pubspec.yaml', cache),
+        cache.sources,
+        expectedName: ref.name,
+        containingDescription: resolvedDescription,
+      );
+    }();
   }
 
   /// Clones a Git repo to the local filesystem.
@@ -680,6 +766,34 @@ class GitSource extends CachedSource {
   String _packageListPath(String revisionCachePath) =>
       p.join(revisionCachePath, '.git/pub-packages');
 
+  ///
+  Future<List<TaggedVersion>> _listTaggedVersions(
+    String path,
+    RegExp compiledTagPattern,
+  ) async {
+    final output = await git.run([
+      'tag',
+      '--list',
+      '--format',
+      // We can use space here, as it is not allowed in a git tag
+      // https://git-scm.com/docs/git-check-ref-format
+      '%(refname:lstrip=2) %(objectname)',
+    ], workingDir: path);
+    final lines = output.trim().split('\n');
+    final result = <TaggedVersion>[];
+    for (final line in lines) {
+      final parts = line.split(' ');
+      if (parts.length != 2) {
+        throw PackageNotFoundException('Bad output from `git tag --list`');
+      }
+      final match = compiledTagPattern.firstMatch(parts[0]);
+      if (match == null) continue;
+      final version = Version.parse(match[1]!);
+      result.add((version: version, commitId: parts[1]));
+    }
+    return result;
+  }
+
   /// Runs "git rev-list" on [reference] in [path] and returns the first result.
   ///
   /// This assumes that the canonical clone already exists.
@@ -793,6 +907,8 @@ class GitDescription extends Description {
   /// not allow strings of the form: 'git@github.com:dart-lang/pub.git'.
   final String url;
 
+  final String? tagPattern;
+
   /// `true` if [url] was parsed from a relative url.
   final bool relative;
 
@@ -804,11 +920,14 @@ class GitDescription extends Description {
   /// Represented as a relative url.
   final String path;
 
+  late final RegExp compiledTagPattern = compileTagPattern(tagPattern!);
+
   GitDescription.raw({
     required this.url,
     required this.relative,
     required String? ref,
     required String? path,
+    required this.tagPattern,
   }) : ref = ref ?? 'HEAD',
        path = path ?? '.';
 
@@ -817,6 +936,7 @@ class GitDescription extends Description {
     required String? ref,
     required String? path,
     required String? containingDir,
+    required String? tagPattern,
   }) {
     final validatedUrl = GitSource._validatedUrl(url, containingDir);
     return GitDescription.raw(
@@ -824,6 +944,7 @@ class GitDescription extends Description {
       relative: validatedUrl.wasRelative,
       ref: ref,
       path: path,
+      tagPattern: tagPattern,
     );
   }
 
@@ -853,6 +974,7 @@ class GitDescription extends Description {
       'url': relativeUrl,
       if (ref != 'HEAD') 'ref': ref,
       if (path != '.') 'path': path,
+      if (tagPattern != null) 'tag_pattern': tagPattern,
     };
   }
 
@@ -867,8 +989,13 @@ class GitDescription extends Description {
         other.path == path;
   }
 
-  GitDescription withRef(String newRef) =>
-      GitDescription.raw(url: url, relative: relative, ref: newRef, path: path);
+  GitDescription withRef(String newRef) => GitDescription.raw(
+    url: url,
+    relative: relative,
+    ref: newRef,
+    path: path,
+    tagPattern: tagPattern,
+  );
 
   @override
   int get hashCode => Object.hash(url, ref, path);
@@ -884,6 +1011,9 @@ class GitDescription extends Description {
     }
     return p.prettyUri(url);
   }
+
+  @override
+  bool get hasMultipleVersions => tagPattern != null;
 }
 
 class ResolvedGitDescription extends ResolvedDescription {
@@ -915,6 +1045,7 @@ class ResolvedGitDescription extends ResolvedDescription {
     return {
       'url': url,
       'ref': description.ref,
+      if (description.tagPattern != null) 'tag-pattern': description.tagPattern,
       'resolved-ref': resolvedRef,
       'path': description.path,
     };
@@ -943,3 +1074,33 @@ String _gitDirArg(String path) {
       Platform.isWindows ? path.replaceAll('\\', '/') : path;
   return '--git-dir=$forwardSlashPath';
 }
+
+final tagPatternPattern = RegExp(r'^(.*){{version}}(.*)$');
+
+// Adapted from pub_semver-2.1.4/lib/src/version.dart
+const versionPattern =
+    r'(\d+)\.(\d+)\.(\d+)' // Version number.
+    r'(-([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*))?' // Pre-release.
+    r'(\+([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*))?'; // build
+
+/// Takes a [tagPattern] and returns a [RegExp] matching the relevant tags.
+///
+/// The tagPattern should contain '{{version}}' which will match a pub_semver
+/// version. The rest of the tagPattern is matched verbatim.
+RegExp compileTagPattern(String tagPattern) {
+  final match = tagPatternPattern.firstMatch(tagPattern);
+  if (match == null) {
+    throw const FormatException(
+      'The `tag_pattern` must contain "{{version}" '
+      'to match different versions',
+    );
+  }
+  final before = RegExp.escape(match[1]!);
+  final after = RegExp.escape(match[2]!);
+
+  return RegExp(
+    r'^'
+    '$before($versionPattern)$after'
+    r'$',
+  );
+}
diff --git a/lib/src/source/hosted.dart b/lib/src/source/hosted.dart
index 1956d9a66..54b98381b 100644
--- a/lib/src/source/hosted.dart
+++ b/lib/src/source/hosted.dart
@@ -123,8 +123,6 @@ class HostedSource extends CachedSource {
 
   @override
   final name = 'hosted';
-  @override
-  final hasMultipleVersions = true;
 
   static String pubDevUrl = 'https://pub.dev';
   static String pubDartlangUrl = 'https://pub.dartlang.org';
@@ -229,7 +227,7 @@ class HostedSource extends CachedSource {
   PackageRef parseRef(
     String name,
     Object? description, {
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
     required LanguageVersion languageVersion,
   }) {
     return PackageRef(
@@ -416,17 +414,22 @@ class HostedSource extends CachedSource {
       if (pubspecData is! Map) {
         throw const FormatException('pubspec must be a map');
       }
+
+      final archiveSha256 = map['archive_sha256'];
+      if (archiveSha256 != null && archiveSha256 is! String) {
+        throw const FormatException('archive_sha256 must be a String');
+      }
+      final parsedContentHash = _parseContentHash(archiveSha256 as String?);
       final pubspec = Pubspec.fromMap(
         pubspecData,
         cache.sources,
         expectedName: ref.name,
         location: location,
-        containingDescription: description,
+        containingDescription: ResolvedHostedDescription(
+          description,
+          sha256: parsedContentHash,
+        ),
       );
-      final archiveSha256 = map['archive_sha256'];
-      if (archiveSha256 != null && archiveSha256 is! String) {
-        throw const FormatException('archive_sha256 must be a String');
-      }
       final archiveUrl = map['archive_url'];
       if (archiveUrl is! String) {
         throw const FormatException('archive_url must be a String');
@@ -451,7 +454,6 @@ class HostedSource extends CachedSource {
         }
         advisoriesDate = DateTime.parse(advisoriesUpdated);
       }
-
       final status = PackageStatus(
         isDiscontinued: isDiscontinued,
         discontinuedReplacedBy: replacedBy,
@@ -463,7 +465,7 @@ class HostedSource extends CachedSource {
         pubspec,
         Uri.parse(archiveUrl),
         status,
-        _parseContentHash(archiveSha256 as String?),
+        parsedContentHash,
       );
     }).toList();
   }
@@ -543,16 +545,20 @@ class HostedSource extends CachedSource {
       if (listing == null || listing.isEmpty) return;
       final latestVersion =
           maxBy<_VersionInfo, Version>(listing, (e) => e.version)!;
-      final dependencies = latestVersion.pubspec.dependencies.values;
-      unawaited(
-        withDependencyType(DependencyType.none, () async {
-          for (final packageRange in dependencies) {
-            if (packageRange.source is HostedSource) {
-              preschedule!(_RefAndCache(packageRange.toRef(), cache));
+      try {
+        final dependencies = latestVersion.pubspec.dependencies.values;
+        unawaited(
+          withDependencyType(DependencyType.none, () async {
+            for (final packageRange in dependencies) {
+              if (packageRange.source is HostedSource) {
+                preschedule!(_RefAndCache(packageRange.toRef(), cache));
+              }
             }
-          }
-        }),
-      );
+          }),
+        );
+      } on FormatException {
+        // Ignore malformed dependencies.
+      }
     }
 
     final cache = refAndCache.cache;
@@ -1640,7 +1646,7 @@ See $contentHashesDocumentationUrl.
           containingDescription:
           // Dummy description. As we never use the dependencies, they don't
           // need to be resolved.
-          RootDescription('.'),
+          ResolvedRootDescription.fromDir('.'),
         );
         final errors = pubspec.dependencyErrors;
         if (errors.isNotEmpty) {
@@ -1813,6 +1819,9 @@ class HostedDescription extends Description {
 
   @override
   HostedSource get source => HostedSource.instance;
+
+  @override
+  bool get hasMultipleVersions => true;
 }
 
 class ResolvedHostedDescription extends ResolvedDescription {
diff --git a/lib/src/source/path.dart b/lib/src/source/path.dart
index 46b6981bd..a5939e771 100644
--- a/lib/src/source/path.dart
+++ b/lib/src/source/path.dart
@@ -54,7 +54,7 @@ class PathSource extends Source {
   PackageRef parseRef(
     String name,
     Object? description, {
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
     LanguageVersion? languageVersion,
   }) {
     if (description is! String) {
@@ -64,30 +64,32 @@ class PathSource extends Source {
     // Resolve the path relative to the containing file path, and remember
     // whether the original path was relative or absolute.
     final isRelative = p.isRelative(dir);
-
-    if (containingDescription is PathDescription) {
+    if (containingDescription is ResolvedPathDescription) {
       return PackageRef(
         name,
         PathDescription(
           isRelative
-              ? p.join(p.absolute(containingDescription.path), dir)
+              ? p.join(p.absolute(containingDescription.description.path), dir)
               : dir,
           isRelative,
         ),
       );
-    } else if (containingDescription is RootDescription) {
+    } else if (containingDescription is ResolvedRootDescription) {
       return PackageRef(
         name,
         PathDescription(
           isRelative
               ? p.normalize(
-                p.join(p.absolute(containingDescription.path), description),
+                p.join(
+                  p.absolute(containingDescription.description.path),
+                  description,
+                ),
               )
               : description,
           isRelative,
         ),
       );
-    } else if (containingDescription is GitDescription) {
+    } else if (containingDescription is ResolvedGitDescription) {
       if (!isRelative) {
         throw FormatException(
           '"$description" is an absolute path, '
@@ -95,7 +97,10 @@ class PathSource extends Source {
         );
       }
       final resolvedPath = p.url.normalize(
-        p.url.joinAll([containingDescription.path, ...p.posix.split(dir)]),
+        p.url.joinAll([
+          containingDescription.description.path,
+          ...p.posix.split(dir),
+        ]),
       );
       if (!(p.isWithin('.', resolvedPath) || p.equals('.', resolvedPath))) {
         throw FormatException(
@@ -106,9 +111,11 @@ class PathSource extends Source {
       return PackageRef(
         name,
         GitDescription.raw(
-          url: containingDescription.url,
-          relative: containingDescription.relative,
-          ref: containingDescription.ref,
+          url: containingDescription.description.url,
+          relative: containingDescription.description.relative,
+          // Always refer to the same commit as the containing pubspec.
+          ref: containingDescription.resolvedRef,
+          tagPattern: null,
           path: resolvedPath,
         ),
       );
@@ -193,12 +200,9 @@ class PathSource extends Source {
     }
     // There's only one package ID for a given path. We just need to find the
     // version.
-    final pubspec = _loadPubspec(ref, cache);
-    final id = PackageId(
-      ref.name,
-      pubspec.version,
-      ResolvedPathDescription(description),
-    );
+    final resolvedDescription = ResolvedPathDescription(description);
+    final pubspec = _loadPubspec(ref, resolvedDescription, cache);
+    final id = PackageId(ref.name, pubspec.version, resolvedDescription);
     // Store the pubspec in memory if we need to refer to it again.
     cache.cachedPubspecs[id] = pubspec;
     return [id];
@@ -206,14 +210,18 @@ class PathSource extends Source {
 
   @override
   Future<Pubspec> doDescribe(PackageId id, SystemCache cache) async =>
-      _loadPubspec(id.toRef(), cache);
+      _loadPubspec(
+        id.toRef(),
+        id.description as ResolvedPathDescription,
+        cache,
+      );
 
-  Pubspec _loadPubspec(PackageRef ref, SystemCache cache) {
-    final description = ref.description;
-    if (description is! PathDescription) {
-      throw ArgumentError('Wrong source');
-    }
-    final dir = _validatePath(ref.name, description);
+  Pubspec _loadPubspec(
+    PackageRef ref,
+    ResolvedPathDescription description,
+    SystemCache cache,
+  ) {
+    final dir = _validatePath(ref.name, description.description);
     return Pubspec.load(
       dir,
       cache.sources,
@@ -306,6 +314,9 @@ class PathDescription extends Description {
 
   @override
   int get hashCode => _canonicalizedPath.hashCode;
+
+  @override
+  bool get hasMultipleVersions => false;
 }
 
 class ResolvedPathDescription extends ResolvedDescription {
diff --git a/lib/src/source/root.dart b/lib/src/source/root.dart
index d6f971ac5..44342bc63 100644
--- a/lib/src/source/root.dart
+++ b/lib/src/source/root.dart
@@ -66,7 +66,7 @@ class RootSource extends Source {
   PackageRef parseRef(
     String name,
     Object? description, {
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
     required LanguageVersion languageVersion,
   }) {
     throw UnsupportedError('Trying to parse a root package description.');
@@ -78,6 +78,7 @@ class ResolvedRootDescription extends ResolvedDescription {
   RootDescription get description => super.description as RootDescription;
 
   ResolvedRootDescription(RootDescription super.description);
+  ResolvedRootDescription.fromDir(String dir) : super(RootDescription(dir));
 
   @override
   Object? serializeForLockfile({required String? containingDir}) {
@@ -118,4 +119,7 @@ class RootDescription extends Description {
 
   @override
   int get hashCode => 'root'.hashCode;
+
+  @override
+  bool get hasMultipleVersions => false;
 }
diff --git a/lib/src/source/sdk.dart b/lib/src/source/sdk.dart
index daaca0920..8469ef6b9 100644
--- a/lib/src/source/sdk.dart
+++ b/lib/src/source/sdk.dart
@@ -29,7 +29,7 @@ class SdkSource extends Source {
   PackageRef parseRef(
     String name,
     Object? description, {
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
     LanguageVersion? languageVersion,
   }) {
     if (description is! String) {
@@ -91,7 +91,9 @@ class SdkSource extends Source {
       _verifiedPackagePath(ref),
       cache.sources,
       expectedName: ref.name,
-      containingDescription: ref.description,
+      containingDescription: ResolvedSdkDescription(
+        ref.description as SdkDescription,
+      ),
     );
 
     /// Validate that there are no non-sdk dependencies if the SDK does not
@@ -186,6 +188,9 @@ class SdkDescription extends Description {
   bool operator ==(Object other) {
     return other is SdkDescription && other.sdk == sdk;
   }
+
+  @override
+  bool get hasMultipleVersions => false;
 }
 
 class ResolvedSdkDescription extends ResolvedDescription {
diff --git a/lib/src/source/unknown.dart b/lib/src/source/unknown.dart
index 50102eaac..8774898c4 100644
--- a/lib/src/source/unknown.dart
+++ b/lib/src/source/unknown.dart
@@ -37,7 +37,7 @@ class UnknownSource extends Source {
   PackageRef parseRef(
     String name,
     Object? description, {
-    required Description containingDescription,
+    required ResolvedDescription containingDescription,
     LanguageVersion? languageVersion,
   }) => PackageRef(name, UnknownDescription(description, this));
 
@@ -111,6 +111,9 @@ class UnknownDescription extends Description {
 
   @override
   int get hashCode => Object.hash(source.name, json.encode(description));
+
+  @override
+  bool get hasMultipleVersions => false;
 }
 
 class ResolvedUnknownDescription extends ResolvedDescription {
diff --git a/test/descriptor/git.dart b/test/descriptor/git.dart
index c52b7dabb..15a43ac7a 100644
--- a/test/descriptor/git.dart
+++ b/test/descriptor/git.dart
@@ -36,6 +36,15 @@ class GitRepoDescriptor extends DirectoryDescriptor {
     ]);
   }
 
+  /// Adds a tag named [tag] to the repo described by `this`.
+  ///
+  /// [parent] defaults to [sandbox].
+  Future tag(String tag, [String? parent]) async {
+    await _runGitCommands(parent, [
+      ['tag', '-a', tag, '-m', 'Some message'],
+    ]);
+  }
+
   /// Return a Future that completes to the commit in the git repository
   /// referred to by [ref].
   ///
diff --git a/test/get/git/check_out_and_upgrade_test.dart b/test/get/git/check_out_and_upgrade_test.dart
index 2bf074327..bbe598a65 100644
--- a/test/get/git/check_out_and_upgrade_test.dart
+++ b/test/get/git/check_out_and_upgrade_test.dart
@@ -61,4 +61,77 @@ void main() {
 
     expect(packageSpec('foo'), isNot(originalFooSpec));
   });
+
+  test('checks out and upgrades a package from with a tag-pattern', () async {
+    ensureGit();
+
+    final repo = d.git('foo.git', [
+      d.libDir('foo'),
+      d.libPubspec('foo', '1.0.0'),
+    ]);
+    await repo.create();
+    await repo.tag('v1.0.0');
+
+    await d
+        .appDir(
+          dependencies: {
+            'foo': {
+              'git': {'url': '../foo.git', 'tag_pattern': 'v{{version}}'},
+              'version': '^1.0.0',
+            },
+          },
+          pubspec: {
+            'environment': {'sdk': '^3.9.0'},
+          },
+        )
+        .create();
+
+    await pubGet(
+      output: contains('+ foo 1.0.0'),
+      environment: {'_PUB_TEST_SDK_VERSION': '3.9.0'},
+    );
+
+    // This should be found by `pub upgrade`.
+    await d.git('foo.git', [
+      d.libDir('foo'),
+      d.libPubspec('foo', '1.5.0'),
+    ]).commit();
+    await repo.tag('v1.5.0');
+
+    // The untagged version should not be found by `pub upgrade`.
+    await d.git('foo.git', [
+      d.libDir('foo'),
+      d.libPubspec('foo', '1.7.0'),
+    ]).commit();
+
+    // This should be found by `pub upgrade --major-versions`
+    await d.git('foo.git', [
+      d.libDir('foo'),
+      d.libPubspec('foo', '2.0.0'),
+    ]).commit();
+    await repo.tag('v2.0.0');
+
+    // A version that is not tagged according to the pattern should not be
+    // chosen by the `upgrade --major-versions`.
+    await d.git('foo.git', [
+      d.libDir('foo'),
+      d.libPubspec('foo', '3.0.0'),
+    ]).commit();
+    await repo.tag('unrelatedTag');
+
+    await pubUpgrade(
+      output: allOf(contains('> foo 1.5.0'), contains('Changed 1 dependency!')),
+      environment: {'_PUB_TEST_SDK_VERSION': '3.9.0'},
+    );
+
+    await pubUpgrade(
+      args: ['--major-versions'],
+      output: allOf(
+        contains('> foo 2.0.0'),
+        contains('foo: ^1.0.0 -> ^2.0.0'),
+        contains('Changed 1 dependency!'),
+      ),
+      environment: {'_PUB_TEST_SDK_VERSION': '3.9.0'},
+    );
+  });
 }
diff --git a/test/get/git/ssh_url_test.dart b/test/get/git/ssh_url_test.dart
index 81bf45e69..43c13f612 100644
--- a/test/get/git/ssh_url_test.dart
+++ b/test/get/git/ssh_url_test.dart
@@ -23,6 +23,11 @@ void main() {
         ref: 'main',
         path: 'abc/',
         containingDir: null,
+        tagPattern: null,
+      );
+      expect(
+        description.format(),
+        'git@github.com:dart-lang/pub.git at main in abc/',
       );
       expect(
         description.format(),
diff --git a/test/get/git/tag_pattern_test.dart b/test/get/git/tag_pattern_test.dart
new file mode 100644
index 000000000..b7bf8d6eb
--- /dev/null
+++ b/test/get/git/tag_pattern_test.dart
@@ -0,0 +1,214 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:path/path.dart' as p;
+import 'package:pub/src/exit_codes.dart';
+import 'package:test/test.dart';
+
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+
+void main() {
+  test('Versions inside a tag_pattern dependency can depend on versions from '
+      'another commit', () async {
+    ensureGit();
+    await d.git('foo.git', [
+      d.libPubspec(
+        'foo',
+        '1.0.0',
+        sdk: '^3.9.0',
+        deps: {
+          'bar': {
+            'git': {
+              'url': p.join(d.sandbox, 'bar'),
+              'tag_pattern': '{{version}}',
+            },
+            'version': '^2.0.0',
+          },
+        },
+      ),
+    ]).create();
+    await d.git('foo.git', []).tag('1.0.0');
+
+    await d.git('foo.git', [
+      d.libPubspec(
+        'foo',
+        '2.0.0',
+        sdk: '^3.9.0',
+        deps: {
+          'bar': {
+            'git': {
+              'url': p.join(d.sandbox, 'bar.git'),
+              'tag_pattern': '{{version}}',
+            },
+            'version': '^1.0.0',
+          },
+        },
+      ),
+    ]).commit();
+    await d.git('foo.git', []).tag('2.0.0');
+
+    await d.git('bar.git', [
+      d.libPubspec(
+        'bar',
+        '1.0.0',
+        sdk: '^3.9.0',
+        deps: {
+          'foo': {
+            'git': {
+              'url': p.join(d.sandbox, 'bar.git'),
+              'tag_pattern': '{{version}}',
+            },
+            'version': '^2.0.0',
+          },
+        },
+      ),
+    ]).create();
+    await d.git('bar.git', []).tag('1.0.0');
+
+    await d.git('bar.git', [
+      d.libPubspec(
+        'bar',
+        '2.0.0',
+        sdk: '^3.9.0',
+        deps: {
+          'foo': {
+            'git': {
+              'url': p.join(d.sandbox, 'foo.git'),
+              'tag_pattern': '{{version}}',
+            },
+            'version': '^1.0.0',
+          },
+        },
+      ),
+    ]).commit();
+    await d.git('bar.git', []).tag('2.0.0');
+
+    await d
+        .appDir(
+          dependencies: {
+            'foo': {
+              'git': {
+                'url': p.join(d.sandbox, 'foo.git'),
+                'tag_pattern': '{{version}}',
+              },
+              'version': '^1.0.0',
+            },
+          },
+          pubspec: {
+            'environment': {'sdk': '^3.9.0'},
+          },
+        )
+        .create();
+
+    await pubGet(
+      output: allOf(contains('+ foo 1.0.0'), contains('+ bar 2.0.0')),
+      environment: {'_PUB_TEST_SDK_VERSION': '3.9.0'},
+    );
+  });
+
+  test('Versions inside a tag_pattern dependency cannot depend on '
+      'version from another commit via path-dependencies', () async {
+    ensureGit();
+
+    await d.git('repo.git', [
+      d.dir('foo', [
+        d.libPubspec(
+          'foo',
+          '1.0.0',
+          deps: {
+            'bar': {'path': '../bar', 'version': '^2.0.0'},
+          },
+        ),
+      ]),
+      d.dir('bar', [
+        d.libPubspec(
+          'bar',
+          '2.0.0',
+          deps: {
+            'foo': {'path': '../foo', 'version': '^1.0.0'},
+          },
+        ),
+      ]),
+    ]).create();
+    await d.git('repo.git', []).tag('foo-1.0.0');
+    await d.git('repo.git', []).tag('bar-2.0.0');
+
+    await d.git('repo.git', [
+      d.dir('foo', [
+        d.libPubspec(
+          'foo',
+          '2.0.0',
+          deps: {
+            'bar': {'path': '../bar', 'version': '^2.0.0'},
+          },
+        ),
+      ]),
+      d.dir('bar', [
+        d.libPubspec(
+          'bar',
+          '1.0.0',
+          deps: {
+            'foo': {'path': '../foo', 'version': '^1.0.0'},
+          },
+        ),
+      ]),
+    ]).commit();
+    await d.git('repo.git', []).tag('foo-2.0.0');
+    await d.git('repo.git', []).tag('bar-1.0.0');
+
+    await d
+        .appDir(
+          dependencies: {
+            'foo': {
+              'git': {
+                'url': '../repo.git',
+                'tag_pattern': 'foo-{{version}}',
+                'path': 'foo',
+              },
+              'version': '^1.0.0',
+            },
+          },
+          pubspec: {
+            'environment': {'sdk': '^3.9.0'},
+          },
+        )
+        .create();
+    final s = RegExp.escape(p.separator);
+    await pubGet(
+      error: matches(
+        'Because foo from git ..${s}repo.git at HEAD in foo '
+        'depends on bar \\^2.0.0 from git '
+        'which depends on foo from git ..${s}repo.git at [a-f0-9]+ in foo, '
+        'foo <2.0.0 from git is forbidden',
+      ),
+      environment: {'_PUB_TEST_SDK_VERSION': '3.9.0'},
+    );
+  });
+
+  test('tag_pattern must contain "{{version}}"', () async {
+    await d
+        .appDir(
+          dependencies: {
+            'foo': {
+              'git': {'url': 'some/git/path', 'tag_pattern': 'v100'},
+            },
+          },
+          pubspec: {
+            'environment': {'sdk': '^3.9.0'},
+          },
+        )
+        .create();
+
+    await pubGet(
+      environment: {'_PUB_TEST_SDK_VERSION': '3.9.0'},
+      error: contains(
+        'Invalid description in the "myapp" pubspec on the "foo" dependency: '
+        'The `tag_pattern` must contain "{{version}" '
+        'to match different versions',
+      ),
+      exitCode: DATA,
+    );
+  });
+}
diff --git a/test/pubspec_test.dart b/test/pubspec_test.dart
index 60db3101d..a3e2ba3f6 100644
--- a/test/pubspec_test.dart
+++ b/test/pubspec_test.dart
@@ -26,7 +26,7 @@ void main() {
       void Function(Pubspec) fn, {
       String? expectedContains,
       String? hintContains,
-      Description? containingDescription,
+      ResolvedDescription? containingDescription,
     }) {
       var expectation = const TypeMatcher<SourceSpanApplicationException>();
       if (expectedContains != null) {
@@ -47,7 +47,8 @@ void main() {
       final pubspec = Pubspec.parse(
         contents,
         sources,
-        containingDescription: containingDescription ?? RootDescription('.'),
+        containingDescription:
+            containingDescription ?? ResolvedRootDescription.fromDir('.'),
       );
       expect(() => fn(pubspec), throwsA(expectation));
     }
@@ -57,7 +58,7 @@ void main() {
       Pubspec.parse(
         'version: not a semver',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
     });
 
@@ -68,7 +69,7 @@ void main() {
           'name: foo',
           sources,
           expectedName: 'bar',
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         ),
         throwsPubspecException,
       );
@@ -81,7 +82,7 @@ void main() {
           '{}',
           sources,
           expectedName: 'bar',
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         ),
         throwsPubspecException,
       );
@@ -98,7 +99,7 @@ dependencies:
     version: ">=1.2.3 <3.4.5"
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       final foo = pubspec.dependencies['foo']!;
@@ -119,7 +120,7 @@ dependencies:
     version: ">=1.2.3 <0.0.0"
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       final foo = pubspec.dependencies['foo']!;
@@ -133,7 +134,7 @@ dependencies:
 dependencies:
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       expect(pubspec.dependencies, isEmpty);
@@ -150,7 +151,7 @@ dev_dependencies:
     version: ">=1.2.3 <3.4.5"
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       final foo = pubspec.devDependencies['foo']!;
@@ -166,7 +167,7 @@ dev_dependencies:
 dev_dependencies:
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       expect(pubspec.devDependencies, isEmpty);
@@ -183,7 +184,7 @@ dependency_overrides:
     version: ">=1.2.3 <3.4.5"
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       final foo = pubspec.dependencyOverrides['foo']!;
@@ -199,7 +200,7 @@ dependency_overrides:
 dependency_overrides:
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       expect(pubspec.dependencyOverrides, isEmpty);
@@ -213,7 +214,7 @@ dependencies:
     unknown: blah
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       final foo = pubspec.dependencies['foo']!;
@@ -229,7 +230,7 @@ dependencies:
     version: 1.2.3
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
 
       final foo = pubspec.dependencies['foo']!;
@@ -344,7 +345,7 @@ environment:
 workspace: ['a', 'b', 'c']
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         ).workspace,
         ['a', 'b', 'c'],
       );
@@ -359,7 +360,7 @@ environment:
 resolution: workspace
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         ).resolution,
         Resolution.workspace,
       );
@@ -393,7 +394,7 @@ environment:
 resolution: workspace
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         ).name,
         'foo',
       );
@@ -451,7 +452,7 @@ resolution: "sometimes"''', (pubspec) => pubspec.resolution);
 # See https://dart.dev/tools/pub/cmd for details
 ''',
         sources,
-        containingDescription: RootDescription('.'),
+        containingDescription: ResolvedRootDescription.fromDir('.'),
       );
       expect(pubspec.version, equals(Version.none));
       expect(pubspec.dependencies, isEmpty);
@@ -464,13 +465,15 @@ name: pkg
 dependencies:
   from_path: {path: non_local_path}
 ''',
-        containingDescription: HostedDescription('foo', 'https://pub.dev'),
+        containingDescription: ResolvedHostedDescription(
+          HostedDescription('foo', 'https://pub.dev'),
+          sha256: null,
+        ),
         (pubspec) => pubspec.dependencies,
         expectedContains:
             'Invalid description in the "pkg" pubspec on the "from_path" '
-            'dependency: "non_local_path" is a relative path, '
-            'but this isn\'t a '
-            'local pubspec.',
+            'dependency: "non_local_path" is a path, but '
+            'this isn\'t a local pubspec.',
       );
     });
 
@@ -486,7 +489,7 @@ dependencies:
       name: bar
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
 
         final foo = pubspec.dependencies['foo']!;
@@ -513,7 +516,7 @@ dependencies:
       url: https://example.org/pub/
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
 
         final foo = pubspec.dependencies['foo']!;
@@ -539,7 +542,7 @@ dependencies:
     hosted: https://example.org/pub/
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
 
         final foo = pubspec.dependencies['foo']!;
@@ -565,7 +568,7 @@ dependencies:
     hosted: bar
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
 
         final foo = pubspec.dependencies['foo']!;
@@ -593,7 +596,7 @@ dependencies:
     hosted: https://example.org/pub/
 ''',
             sources,
-            containingDescription: RootDescription('.'),
+            containingDescription: ResolvedRootDescription.fromDir('.'),
           );
 
           expect(
@@ -617,7 +620,7 @@ dependencies:
   foo:
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
 
         final foo = pubspec.dependencies['foo']!;
@@ -715,7 +718,7 @@ dependencies:
         final pubspec = Pubspec.parse(
           'name: testing',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(
           pubspec.dartSdkConstraint.effectiveConstraint,
@@ -730,7 +733,7 @@ dependencies:
         final pubspec = Pubspec.parse(
           '',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(
           pubspec.dartSdkConstraint.effectiveConstraint,
@@ -748,7 +751,7 @@ dependencies:
     sdk: ">1.0.0"
   ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(
           pubspec.dartSdkConstraint.effectiveConstraint,
@@ -766,7 +769,7 @@ dependencies:
     sdk: ">3.0.0"
   ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(
           pubspec.sdkConstraints,
@@ -795,7 +798,7 @@ environment:
   fuchsia: ^5.6.7
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(
           pubspec.sdkConstraints,
@@ -859,7 +862,7 @@ environment:
         final pubspec = Pubspec.parse(
           '',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(pubspec.publishTo, isNull);
       });
@@ -877,7 +880,7 @@ environment:
 publish_to: http://example.com
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(pubspec.publishTo, equals('http://example.com'));
       });
@@ -888,7 +891,7 @@ publish_to: http://example.com
 publish_to: none
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(pubspec.publishTo, equals('none'));
       });
@@ -913,7 +916,7 @@ publish_to: none
         final pubspec = Pubspec.parse(
           '',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(pubspec.executables, isEmpty);
       });
@@ -925,7 +928,7 @@ executables:
   abcDEF-123_: "abc DEF-123._"
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(pubspec.executables['abcDEF-123_'], equals('abc DEF-123._'));
       });
@@ -979,7 +982,7 @@ executables:
   command:
 ''',
           sources,
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
         expect(pubspec.executables['command'], equals('command'));
       });
@@ -998,7 +1001,7 @@ dependency_overrides:
           sources,
           overridesFileContents: overridesContents,
           overridesLocation: Uri.parse('file:///pubspec_overrides.yaml'),
-          containingDescription: RootDescription('.'),
+          containingDescription: ResolvedRootDescription.fromDir('.'),
         );
       }
 
diff --git a/test/version_solver_test.dart b/test/version_solver_test.dart
index c0ec3709f..dcf5a4241 100644
--- a/test/version_solver_test.dart
+++ b/test/version_solver_test.dart
@@ -520,26 +520,34 @@ Because myapp depends on foo ^1.0.0 which doesn't match any versions, version so
 
   test('mismatched sources', () async {
     await d.dir('shared', [d.libPubspec('shared', '1.0.0')]).create();
-
-    await servePackages()
-      ..serve('foo', '1.0.0', deps: {'shared': '1.0.0'})
-      ..serve(
+    await d.dir('bar', [
+      d.libPubspec(
         'bar',
         '1.0.0',
         deps: {
           'shared': {'path': p.join(d.sandbox, 'shared')},
         },
-      )
+      ),
+    ]).create();
+    await servePackages()
+      ..serve('foo', '1.0.0', deps: {'shared': '1.0.0'})
       ..serve('shared', '1.0.0');
 
-    await d.appDir(dependencies: {'foo': '1.0.0', 'bar': '1.0.0'}).create();
+    await d
+        .appDir(
+          dependencies: {
+            'foo': '1.0.0',
+            'bar': {'path': '../bar'},
+          },
+        )
+        .create();
     await expectResolves(
       error: equalsIgnoringWhitespace('''
-      Because every version of bar depends on shared from path and every
-        version of foo depends on shared from hosted, bar is incompatible with
-        foo.
-      So, because myapp depends on both foo 1.0.0 and bar 1.0.0, version
-        solving failed.
+ Because every version of bar from path depends on shared
+ from path and every version of foo depends on shared from hosted,
+ bar from path is incompatible with foo.
+So, because myapp depends on both foo 1.0.0 and bar from path,
+version solving failed.
     '''),
     );
   });
@@ -888,7 +896,7 @@ void backtracking() {
   // dependencies are traversed breadth-first (all of myapps's immediate deps
   // before any other their deps).
   //
-  // This means it doesn't discover the source conflict until after selecting
+  // This means it doesn't discover the version conflict until after selecting
   // c. When that happens, it should backjump past c instead of trying older
   // versions of it since they aren't related to the conflict.
   test('successful backjump to conflicting source', () async {
@@ -896,21 +904,18 @@ void backtracking() {
 
     await servePackages()
       ..serve('a', '1.0.0')
+      ..serve('a', '2.0.0')
       ..serve('b', '1.0.0', deps: {'a': 'any'})
-      ..serve(
-        'b',
-        '2.0.0',
-        deps: {
-          'a': {'path': p.join(d.sandbox, 'a')},
-        },
-      )
+      ..serve('b', '2.0.0', deps: {'a': '^2.0.0'})
       ..serve('c', '1.0.0')
       ..serve('c', '2.0.0')
       ..serve('c', '3.0.0')
       ..serve('c', '4.0.0')
       ..serve('c', '5.0.0');
 
-    await d.appDir(dependencies: {'a': 'any', 'b': 'any', 'c': 'any'}).create();
+    await d
+        .appDir(dependencies: {'a': '1.0.0', 'b': 'any', 'c': 'any'})
+        .create();
     await expectResolves(result: {'a': '1.0.0', 'b': '1.0.0', 'c': '5.0.0'});
   });
 
@@ -945,29 +950,39 @@ void backtracking() {
   // fail in this case with no backtracking.
   test('failing backjump to conflicting source', () async {
     await d.dir('a', [d.libPubspec('a', '1.0.0')]).create();
-
-    await servePackages()
-      ..serve('a', '1.0.0')
-      ..serve(
+    await d.dir('b', [
+      d.libPubspec(
         'b',
         '1.0.0',
         deps: {
           'a': {'path': p.join(d.sandbox, 'shared')},
         },
-      )
+      ),
+    ]).create();
+
+    await servePackages()
+      ..serve('a', '1.0.0')
       ..serve('c', '1.0.0')
       ..serve('c', '2.0.0')
       ..serve('c', '3.0.0')
       ..serve('c', '4.0.0')
       ..serve('c', '5.0.0');
 
-    await d.appDir(dependencies: {'a': 'any', 'b': 'any', 'c': 'any'}).create();
+    await d
+        .appDir(
+          dependencies: {
+            'a': 'any',
+            'b': {'path': '../b'},
+            'c': 'any',
+          },
+        )
+        .create();
     await expectResolves(
       error: equalsIgnoringWhitespace('''
-      Because every version of b depends on a from path and myapp depends on
-        a from hosted, b is forbidden.
-      So, because myapp depends on b any, version solving failed.
-    '''),
+Because every version of b from path depends on a from path 
+and myapp depends on a from hosted, b from path is forbidden.
+So, because myapp depends on b from path, version solving failed.
+'''),
     );
   });
 
@@ -1983,7 +1998,7 @@ Future expectResolves({
   final resultPubspec = Pubspec.fromMap(
     {'dependencies': result},
     registry,
-    containingDescription: RootDescription('.'),
+    containingDescription: ResolvedRootDescription.fromDir('.'),
   );
 
   final ids = {...lockFile.packages};