getdeps: eliminate per-dep cache pyramid; enable sccache by default

Summary:
Our GHA workflows did not previously use sccache, so they had a complex per-dep cache pyramid. Now they do use sccache.

sccache works on a per-file level so it can accelerate builds even when a dependency has changed.

Now that we have this new caching mechanism we can retire the cache pyramid for a significant reduction in workflow complexity. Trying that here.

Flip `--use-build-cache` to off by default. The pyramid is now opt-in via `--use-build-cache`; sccache remains on by default for all non-Windows platforms (it was already the default — this change makes the pyramid the non-default).

Golden test fixtures are regenerated to match the new output shape.

Reviewed By: bigfootjon

Differential Revision: D105903053

fbshipit-source-id: 8eb0fa3afa0de8975752710bb695619d2453d2c4

Author: r-barnes

.github/workflows/getdeps_linux.yml

@@ -39,39 +39,13 @@ jobs:
       name: Query paths
       run: python3 build/fbcode_builder/getdeps.py query-paths --recursive --src-dir=. xxhash  >> "$GITHUB_OUTPUT"
 
-    - name: Restore ninja from cache
-      id: restore_ninja
-      if: ${{ steps.paths.outputs.ninja_SOURCE }}
-      uses: actions/cache/restore@v4
-      with:
-       path: ${{ steps.paths.outputs.ninja_INSTALL }}
-       key: ${{ steps.paths.outputs.ninja_CACHE_KEY }}-install
     - name: Build ninja
-      if: ${{ steps.paths.outputs.ninja_SOURCE && ! steps.restore_ninja.outputs.cache-hit }}
+      if: ${{ steps.paths.outputs.ninja_SOURCE }}
       run: python3 build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --no-tests ninja
-    - name: Save ninja to cache
-      uses: actions/cache/save@v4
-      if: ${{ steps.paths.outputs.ninja_SOURCE && ! steps.restore_ninja.outputs.cache-hit }}
-      with:
-       path: ${{ steps.paths.outputs.ninja_INSTALL }}
-       key: ${{ steps.paths.outputs.ninja_CACHE_KEY }}-install
 
-    - name: Restore cmake from cache
-      id: restore_cmake
-      if: ${{ steps.paths.outputs.cmake_SOURCE }}
-      uses: actions/cache/restore@v4
-      with:
-       path: ${{ steps.paths.outputs.cmake_INSTALL }}
-       key: ${{ steps.paths.outputs.cmake_CACHE_KEY }}-install
     - name: Build cmake
-      if: ${{ steps.paths.outputs.cmake_SOURCE && ! steps.restore_cmake.outputs.cache-hit }}
+      if: ${{ steps.paths.outputs.cmake_SOURCE }}
       run: python3 build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --no-tests cmake
-    - name: Save cmake to cache
-      uses: actions/cache/save@v4
-      if: ${{ steps.paths.outputs.cmake_SOURCE && ! steps.restore_cmake.outputs.cache-hit }}
-      with:
-       path: ${{ steps.paths.outputs.cmake_INSTALL }}
-       key: ${{ steps.paths.outputs.cmake_CACHE_KEY }}-install
 
     - name: Build xxhash
       run: python3 build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --src-dir=. xxhash --project-install-prefix xxhash:/usr/local

build/fbcode_builder/getdeps/test/fixtures/expected/folly_shared_libs/getdeps_shared-libs_linux.yml

@@ -45,39 +45,13 @@ jobs:
       name: Query paths
       run: python3 build/fbcode_builder/getdeps.py query-paths --recursive --src-dir=. xxhash  >> "$GITHUB_OUTPUT"
 
-    - name: Restore ninja from cache
-      id: restore_ninja
-      if: ${{ steps.paths.outputs.ninja_SOURCE }}
-      uses: actions/cache/restore@v4
-      with:
-       path: ${{ steps.paths.outputs.ninja_INSTALL }}
-       key: ${{ steps.paths.outputs.ninja_CACHE_KEY }}-install
     - name: Build ninja
-      if: ${{ steps.paths.outputs.ninja_SOURCE && ! steps.restore_ninja.outputs.cache-hit }}
+      if: ${{ steps.paths.outputs.ninja_SOURCE }}
       run: python3 build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --no-tests ninja
-    - name: Save ninja to cache
-      uses: actions/cache/save@v4
-      if: ${{ steps.paths.outputs.ninja_SOURCE && ! steps.restore_ninja.outputs.cache-hit }}
-      with:
-       path: ${{ steps.paths.outputs.ninja_INSTALL }}
-       key: ${{ steps.paths.outputs.ninja_CACHE_KEY }}-install
 
-    - name: Restore cmake from cache
-      id: restore_cmake
-      if: ${{ steps.paths.outputs.cmake_SOURCE }}
-      uses: actions/cache/restore@v4
-      with:
-       path: ${{ steps.paths.outputs.cmake_INSTALL }}
-       key: ${{ steps.paths.outputs.cmake_CACHE_KEY }}-install
     - name: Build cmake
-      if: ${{ steps.paths.outputs.cmake_SOURCE && ! steps.restore_cmake.outputs.cache-hit }}
+      if: ${{ steps.paths.outputs.cmake_SOURCE }}
       run: python3 build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --no-tests cmake
-    - name: Save cmake to cache
-      uses: actions/cache/save@v4
-      if: ${{ steps.paths.outputs.cmake_SOURCE && ! steps.restore_cmake.outputs.cache-hit }}
-      with:
-       path: ${{ steps.paths.outputs.cmake_INSTALL }}
-       key: ${{ steps.paths.outputs.cmake_CACHE_KEY }}-install
 
     - name: Build xxhash
       run: python3 build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --src-dir=. xxhash --project-install-prefix xxhash:/usr/local

build/fbcode_builder/getdeps/test/fixtures/expected/openr/getdeps_linux.yml

@@ -18,6 +18,8 @@ jobs:
   build:
     runs-on: windows-2022
     timeout-minutes: 60
+    env:
+      SCCACHE_GHA_ENABLED: "on"
     steps:
 
     - name: Show runner info
@@ -40,48 +42,31 @@ jobs:
 
     - uses: actions/checkout@v6
 
+    - name: Set up sccache
+      uses: mozilla-actions/sccache-action@v0.0.9
+      with:
+        version: "v0.14.0"
+
     - id: paths
       name: Query paths
       run: python build/fbcode_builder/getdeps.py query-paths --recursive --src-dir=. xxhash  >> $env:GITHUB_OUTPUT
       shell: pwsh
 
-    - name: Restore ninja from cache
-      id: restore_ninja
-      if: ${{ steps.paths.outputs.ninja_SOURCE }}
-      uses: actions/cache/restore@v4
-      with:
-       path: ${{ steps.paths.outputs.ninja_INSTALL }}
-       key: ${{ steps.paths.outputs.ninja_CACHE_KEY }}-install
     - name: Build ninja
-      if: ${{ steps.paths.outputs.ninja_SOURCE && ! steps.restore_ninja.outputs.cache-hit }}
+      if: ${{ steps.paths.outputs.ninja_SOURCE }}
       run: python build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --no-tests ninja
-    - name: Save ninja to cache
-      uses: actions/cache/save@v4
-      if: ${{ steps.paths.outputs.ninja_SOURCE && ! steps.restore_ninja.outputs.cache-hit }}
-      with:
-       path: ${{ steps.paths.outputs.ninja_INSTALL }}
-       key: ${{ steps.paths.outputs.ninja_CACHE_KEY }}-install
 
-    - name: Restore cmake from cache
-      id: restore_cmake
-      if: ${{ steps.paths.outputs.cmake_SOURCE }}
-      uses: actions/cache/restore@v4
-      with:
-       path: ${{ steps.paths.outputs.cmake_INSTALL }}
-       key: ${{ steps.paths.outputs.cmake_CACHE_KEY }}-install
     - name: Build cmake
-      if: ${{ steps.paths.outputs.cmake_SOURCE && ! steps.restore_cmake.outputs.cache-hit }}
+      if: ${{ steps.paths.outputs.cmake_SOURCE }}
       run: python build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --no-tests cmake
-    - name: Save cmake to cache
-      uses: actions/cache/save@v4
-      if: ${{ steps.paths.outputs.cmake_SOURCE && ! steps.restore_cmake.outputs.cache-hit }}
-      with:
-       path: ${{ steps.paths.outputs.cmake_INSTALL }}
-       key: ${{ steps.paths.outputs.cmake_CACHE_KEY }}-install
 
     - name: Build xxhash
       run: python build/fbcode_builder/getdeps.py build --build-type RelWithDebInfo --src-dir=. xxhash
 
+    - name: Show sccache stats
+      if: always()
+      run: sccache --show-stats
+
     - name: Copy artifacts
       run: python build/fbcode_builder/getdeps.py fixup-dyn-deps --src-dir=. xxhash _artifacts/windows --final-install-prefix /usr/local
     - uses: actions/upload-artifact@v6

build/fbcode_builder/getdeps/test/fixtures/expected/rebalancer_linux/getdeps_linux.yml

@@ -78,7 +78,7 @@ def _make_args(project: str, output_dir: str, **overrides: Any) -> argparse.Name
         "free_up_disk": False,
         "free_up_disk_before_build": False,
         "build_type": "RelWithDebInfo",
-        "use_build_cache": True,
+        "use_build_cache": False,
         "package_extra_cmake_defines": [],
         "scratch_path": None,
         "vcvars_path": None,

build/fbcode_builder/getdeps/test/fixtures/expected/xxhash_plain/getdeps_linux.yml

@@ -87,7 +87,7 @@ def gh(key):
 
         run_tests = args.enable_tests and gh("run_tests") != "off"
         rust_version = gh("rust_version") or "stable"
-        use_sccache = gh("sccache") != "off" and not build_opts.is_windows()
+        use_sccache = gh("sccache") != "off"
         use_homebrew_llvm = build_opts.is_darwin()
         override_build_type = args.build_type or gh("build_type")
         timeout_minutes = gh("timeout_minutes") or "60"
@@ -430,11 +430,11 @@ def setup_project_cmd_parser(self, parser):
         )
         parser.add_argument("--build-type", **BUILD_TYPE_ARG)
         parser.add_argument(
-            "--no-build-cache",
-            action="store_false",
-            default=True,
+            "--use-build-cache",
+            action="store_true",
+            default=False,
             dest="use_build_cache",
-            help="Do not attempt to use the build cache.",
+            help="Emit a per-dep actions/cache restore/save pyramid. Disabled by default; sccache handles compile-unit caching instead.",
         )
         parser.add_argument(
             "--package-extra-cmake-defines",