Expanded support for SCons variables declared in the legacy format ``…

…${SCONS_VARNAME}`` // Resolve #4828

platformio/project/config.py

@@ -348,7 +348,7 @@ def _re_interpolation_handler(self, parent_section, parent_option, match):
             if option in self.BUILTIN_VARS:
                 return self.BUILTIN_VARS[option]()
             # SCons varaibles
-            return f"${option}"
+            return f"${{{option}}}"
 
         # handle system environment variables
         if section == "sysenv":

tests/project/test_config.py

@@ -660,12 +660,14 @@ def test_nested_interpolation(tmp_path: Path):
 build_flags =
     -D UTIME=${UNIX_TIME}
     -I ${PROJECTSRC_DIR}/hal
+    -Wl,-Map,${BUILD_DIR}/${PROGNAME}.map
 test_testing_command =
     ${platformio.packages_dir}/tool-simavr/bin/simavr
      -m
      atmega328p
      -f
      16000000L
+     ${UPLOAD_PORT and "-p "+UPLOAD_PORT}
      ${platformio.build_dir}/${this.__env__}/firmware.elf
     """
     )
@@ -674,9 +676,14 @@ def test_nested_interpolation(tmp_path: Path):
         os.path.join("$PROJECT_DIR", "assets")
     )
     assert config.get("env:myenv", "build_flags")[0][-10:].isdigit()
-    assert config.get("env:myenv", "build_flags")[1] == "-I $PROJECTSRC_DIR/hal"
+    assert config.get("env:myenv", "build_flags")[1] == "-I ${PROJECTSRC_DIR}/hal"
+    assert (
+        config.get("env:myenv", "build_flags")[2]
+        == "-Wl,-Map,${BUILD_DIR}/${PROGNAME}.map"
+    )
     testing_command = config.get("env:myenv", "test_testing_command")
-    assert "$" not in " ".join(testing_command)
+    assert "$" not in testing_command[0]
+    assert testing_command[5] == '${UPLOAD_PORT and "-p "+UPLOAD_PORT}'
 
 
 def test_extends_order(tmp_path: Path):