Merge branch 'main' into main

.github/workflows/bazel.yml

@@ -78,30 +78,17 @@ jobs:
         shell: bash
         run: ./scripts/check-module-bazel-lock.sh
 
-      # TODO(mbolin): Bring this back once we have caching working. Currently,
-      # we never seem to get a cache hit but we still end up paying the cost of
-      # uploading at the end of the build, which takes over a minute!
-      #
-      # Cache build and external artifacts so that the next ci build is incremental.
-      # Because github action caches cannot be updated after a build, we need to
-      # store the contents of each build in a unique cache key, then fall back to loading
-      # it on the next ci run. We use hashFiles(...) in the key and restore-keys- with
-      # the prefix to load the most recent cache for the branch on a cache miss. You
-      # should customize the contents of hashFiles to capture any bazel input sources,
-      # although this doesn't need to be perfect. If none of the input sources change
-      # then a cache hit will load an existing cache and bazel won't have to do any work.
-      # In the case of a cache miss, you want the fallback cache to contain most of the
-      # previously built artifacts to minimize build time. The more precise you are with
-      # hashFiles sources the less work bazel will have to do.
-      # - name: Mount bazel caches
-      #   uses: actions/cache@v5
-      #   with:
-      #     path: |
-      #       ~/.cache/bazel-repo-cache
-      #       ~/.cache/bazel-repo-contents-cache
-      #     key: bazel-cache-${{ matrix.os }}-${{ hashFiles('**/BUILD.bazel', '**/*.bzl', 'MODULE.bazel') }}
-      #     restore-keys: |
-      #       bazel-cache-${{ matrix.os }}
+      # Restore bazel repository cache so we don't have to redownload all the external dependencies
+      # on every CI run.
+      - name: Restore bazel repository cache
+        id: cache_bazel_repository_restore
+        uses: actions/cache/restore@v5
+        with:
+          path: |
+            ~/.cache/bazel-repo-cache
+          key: bazel-cache-${{ matrix.os }}-${{ hashFiles('MODULE.bazel', 'codex-rs/Cargo.lock', 'codex-rs/Cargo.toml') }}
+          restore-keys: |
+            bazel-cache-${{ matrix.os }}
 
       - name: Configure Bazel startup args (Windows)
         if: runner.os == 'Windows'
@@ -229,3 +216,14 @@ jobs:
             print_failed_bazel_test_logs "$bazel_console_log"
             exit "$bazel_status"
           fi
+
+      # Save bazel repository cache explicitly; make non-fatal so cache uploading
+      # never fails the overall job. Only save when key wasn't hit.
+      - name: Save bazel repository cache
+        if: always() && !cancelled() && steps.cache_bazel_repository_restore.outputs.cache-hit != 'true'
+        continue-on-error: true
+        uses: actions/cache/save@v5
+        with:
+          path: |
+            ~/.cache/bazel-repo-cache
+          key: bazel-cache-${{ matrix.os }}-${{ hashFiles('MODULE.bazel', 'codex-rs/Cargo.lock', 'codex-rs/Cargo.toml') }}