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

@@ -66,9 +66,9 @@ jobs:
     needs: build-tarball
     runs-on: ubuntu-24.04
     env:
-      CC: sccache clang
-      CXX: sccache clang++
-      SCCACHE_GHA_ENABLED: 'true'
+      CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang
+      CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++
+      SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8  # v5.0.0
         with:
@@ -80,6 +80,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - 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

@@ -36,9 +36,9 @@ concurrency:
 env:
   PYTHON_VERSION: '3.14'
   FLAKY_TESTS: keep_retrying
-  CC: sccache clang
-  CXX: sccache clang++
-  SCCACHE_GHA_ENABLED: 'true'
+  CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang
+  CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++
+  SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 
 permissions:
   contents: read
@@ -57,6 +57,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - 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

@@ -36,9 +36,9 @@ concurrency:
 env:
   PYTHON_VERSION: '3.14'
   FLAKY_TESTS: keep_retrying
-  CC: sccache clang
-  CXX: sccache clang++
-  SCCACHE_GHA_ENABLED: 'true'
+  CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang
+  CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++
+  SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 
 permissions:
   contents: read
@@ -57,6 +57,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - 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

@@ -33,9 +33,9 @@ concurrency:
 env:
   PYTHON_VERSION: '3.14'
   FLAKY_TESTS: keep_retrying
-  CC: sccache clang
-  CXX: sccache clang++
-  SCCACHE_GHA_ENABLED: 'true'
+  CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang
+  CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++
+  SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 
 permissions:
   contents: read
@@ -53,6 +53,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - 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

@@ -31,9 +31,9 @@ concurrency:
 env:
   PYTHON_VERSION: '3.14'
   FLAKY_TESTS: keep_retrying
-  CC: sccache clang
-  CXX: sccache clang++
-  SCCACHE_GHA_ENABLED: 'true'
+  CC: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang
+  CXX: ${{ (github.base_ref == 'main' || github.ref_name == 'main') && 'sccache' || '' }} clang++
+  SCCACHE_GHA_ENABLED: ${{ github.base_ref == 'main' || github.ref_name == 'main' }}
 
 permissions:
   contents: read
@@ -56,6 +56,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - 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

@@ -45,9 +45,9 @@ jobs:
       fail-fast: false
     runs-on: macos-14
     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' }}
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8  # v5.0.0
         with:
@@ -60,6 +60,7 @@ 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