build: skip sscache action on non-main branches

To reduce cache thrashing.
PR-URL: #61790
Refs: #61436
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Tierney Cyren <hello@bnb.im>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: joyeecheung

.github/workflows/build-tarball.yml

@@ -100,9 +100,9 @@ jobs:
 needs: build-tarball
 runs-on: ubuntu-24.04
 env:
-CC: sccache clang-19
-CXX: sccache clang++-19
-SCCACHE_GHA_ENABLED: 'true'
+CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang-19
+CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++-19
+SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 SCCACHE_IDLE_TIMEOUT: '0'
 steps:
  - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -120,6 +120,7 @@ jobs:
 python-version: ${{ env.PYTHON_VERSION }}
 allow-prereleases: true
  - name: Set up sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: Mozilla-Actions/sccache-action@7d986dd989559c6ecdb630a3fd2557667be217ad # v0.0.9
 with:
 version: v0.12.0

.github/workflows/coverage-linux-without-intl.yml

@@ -37,9 +37,9 @@ env:
 PYTHON_VERSION: '3.14'
 FLAKY_TESTS: keep_retrying
 CLANG_VERSION: '19'
-CC: sccache clang-19
-CXX: sccache clang++-19
-SCCACHE_GHA_ENABLED: 'true'
+CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang-19
+CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++-19
+SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 SCCACHE_IDLE_TIMEOUT: '0'
 
 permissions:
@@ -63,6 +63,7 @@ jobs:
 python-version: ${{ env.PYTHON_VERSION }}
 allow-prereleases: true
  - name: Set up sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: Mozilla-Actions/sccache-action@7d986dd989559c6ecdb630a3fd2557667be217ad # v0.0.9
 with:
 version: v0.12.0

.github/workflows/coverage-linux.yml

@@ -37,9 +37,9 @@ env:
 PYTHON_VERSION: '3.14'
 FLAKY_TESTS: keep_retrying
 CLANG_VERSION: '19'
-CC: sccache clang-19
-CXX: sccache clang++-19
-SCCACHE_GHA_ENABLED: 'true'
+CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang-19
+CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++-19
+SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 SCCACHE_IDLE_TIMEOUT: '0'
 
 permissions:
@@ -63,6 +63,7 @@ jobs:
 python-version: ${{ env.PYTHON_VERSION }}
 allow-prereleases: true
  - name: Set up sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: Mozilla-Actions/sccache-action@7d986dd989559c6ecdb630a3fd2557667be217ad # v0.0.9
 with:
 version: v0.12.0

.github/workflows/test-internet.yml

@@ -34,9 +34,9 @@ env:
 PYTHON_VERSION: '3.14'
 FLAKY_TESTS: keep_retrying
 CLANG_VERSION: '19'
-CC: sccache clang-19
-CXX: sccache clang++-19
-SCCACHE_GHA_ENABLED: 'true'
+CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang-19
+CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++-19
+SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 SCCACHE_IDLE_TIMEOUT: '0'
 
 permissions:
@@ -60,6 +60,7 @@ jobs:
 python-version: ${{ env.PYTHON_VERSION }}
 allow-prereleases: true
  - name: Set up sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: Mozilla-Actions/sccache-action@7d986dd989559c6ecdb630a3fd2557667be217ad # v0.0.9
 with:
 version: v0.12.0

.github/workflows/test-linux.yml

@@ -34,9 +34,9 @@ env:
 PYTHON_VERSION: '3.14'
 FLAKY_TESTS: keep_retrying
 CLANG_VERSION: '19'
-CC: sccache clang-19
-CXX: sccache clang++-19
-SCCACHE_GHA_ENABLED: 'true'
+CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang-19
+CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++-19
+SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 SCCACHE_IDLE_TIMEOUT: '0'
 
 permissions:
@@ -65,6 +65,7 @@ jobs:
 python-version: ${{ env.PYTHON_VERSION }}
 allow-prereleases: true
  - name: Set up sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: Mozilla-Actions/sccache-action@7d986dd989559c6ecdb630a3fd2557667be217ad # v0.0.9
 with:
 version: v0.12.0

.github/workflows/test-macos.yml

@@ -77,9 +77,9 @@ jobs:
 fail-fast: false
 runs-on: macos-15
 env:
-CC: sccache gcc
-CXX: sccache g++
-SCCACHE_GHA_ENABLED: 'true'
+CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} gcc
+CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} g++
+SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 SCCACHE_IDLE_TIMEOUT: '0'
 steps:
  - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -94,6 +94,7 @@ jobs:
  - name: Set up Xcode ${{ env.XCODE_VERSION }}
 run: sudo xcode-select -s /Applications/Xcode_${{ env.XCODE_VERSION }}.app
  - name: Set up sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: Mozilla-Actions/sccache-action@7d986dd989559c6ecdb630a3fd2557667be217ad # v0.0.9
 with:
 version: v0.12.0

.github/workflows/test-shared.yml

@@ -175,6 +175,7 @@ jobs:
 authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
 
  - name: Configure sccache
+if: github.base_ref == 'main' || github.ref_name == 'main'
 uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
 with:
 script: |