Initialize JEKYLL_BUILD_REVISION with GITHUB_SHA

action.yml.erb

@@ -15,6 +15,10 @@ inputs:
     description: 'Publishes posts with a future date.'
     required: false
     default: true
+  build_revision:
+    description: 'The SHA-1 of the git commit for which the build is running. Default to GITHUB_SHA when not provided.'
+    required: false
+    default:
   verbose:
     description: 'Verbose output'
     required: false

entrypoint.sh

@@ -17,6 +17,7 @@ GITHUB_PAGES=$PAGES_GEM_HOME/bin/github-pages
 export JEKYLL_ENV="production"
 export JEKYLL_GITHUB_TOKEN=$INPUT_TOKEN
 export PAGES_REPO_NWO=$GITHUB_REPOSITORY
+export JEKYLL_BUILD_REVISION=${INPUT_BUILD_REVISION:="$GITHUB_SHA"}
 
 # Set verbose flag
 if [ "$INPUT_VERBOSE" = 'true' ]; then