From 59bad58a5edce47e322227689552d292560c0fcc Mon Sep 17 00:00:00 2001
From: Tom Limoncelli <tal@whatexit.org>
Date: Tue, 25 Aug 2026 16:38:04 -0400
Subject: [PATCH] CI: Add advanced CodeQL workflow that installs Go from go.mod

CodeQL's managed "default setup" runs the Go extractor's autobuild with
the runner's pre-installed Go and GOTOOLCHAIN=local, which forbids
downloading a newer toolchain. Now that go.mod requires `go 1.27` but the
CodeQL runner only ships Go 1.26.x, extraction fails before compiling:

  go: go.mod requires go >= 1.27 (running go 1.26.7; GOTOOLCHAIN=local)
  Extraction failed for all discovered Go projects.
  CodeQL job status was configuration error.

Replace default setup with an advanced workflow that runs
actions/setup-go with go-version-file: go.mod before init/autobuild, so
the required toolchain is the "local" one and GOTOOLCHAIN=local is
satisfied.

NOTE: Default setup must be disabled in the repo settings
(Settings -> Code security -> CodeQL analysis: Default -> Advanced),
otherwise the two configurations conflict.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .github/workflows/codeql.yml | 59 ++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 .github/workflows/codeql.yml

diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
new file mode 100644
index 0000000000..fab2960a3b
--- /dev/null
+++ b/.github/workflows/codeql.yml
@@ -0,0 +1,59 @@
+name: "CodeQL"
+
+# Advanced CodeQL setup.
+#
+# This replaces GitHub's "default setup" for CodeQL. The default setup runs the
+# Go extractor's autobuild with whatever Go is pre-installed on the runner and
+# with GOTOOLCHAIN=local, which forbids downloading a newer toolchain. When
+# go.mod requires a Go version newer than the runner's (e.g. `go 1.27` while the
+# runner only has 1.26.x), extraction fails with:
+#
+#   go: go.mod requires go >= 1.27 (running go 1.26.x; GOTOOLCHAIN=local)
+#
+# Installing Go from go.mod before the extractor runs makes the required
+# toolchain the "local" one, so autobuild succeeds.
+#
+# NOTE: An advanced workflow and the repository's "default setup" cannot both be
+# active. Disable default setup under
+# Settings -> Code security -> CodeQL analysis (switch Default -> Advanced).
+
+on:
+  push:
+    branches: [main, master, release_candidate_v5]
+  pull_request:
+    branches: [main, master, release_candidate_v5]
+  schedule:
+    - cron: "0 0 * * 1"
+
+concurrency:
+  group: codeql-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  analyze:
+    name: Analyze (go)
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      actions: read
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      - name: Set up Go
+        uses: actions/setup-go@v7
+        with:
+          go-version-file: go.mod
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v4
+        with:
+          languages: go
+          build-mode: autobuild
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v4
+        with:
+          category: "/language:go"