refactor: move preflight to ubuntu-slim, skip build on non-star instead of failing

Author: LongQT-sea

.github/workflows/build-macos-image.yml

@@ -34,23 +34,23 @@ on:
           - 'dmg'
 
 jobs:
-  build-macos-image:
+  preflight:
     if: ${{ inputs.macos_version != '' && inputs.image_format != '' }}
-    runs-on: macos-15-intel
-    timeout-minutes: 80
+    runs-on: ubuntu-slim
+    timeout-minutes: 5
+    outputs:
+      _build: ${{ steps.check.outputs._build }}
 
     steps:
       - name: Preflight
+        id: check
         run: |
           # Third time's the charm
           if [ "$GITHUB_RUN_ATTEMPT" -ge 3 ] || [ "$GITHUB_RUN_NUMBER" -ge 3 ]; then
+            echo "_build=true" >> $GITHUB_OUTPUT
             exit 0
           fi
 
-          # Most users arrive directly at the Actions tab without reading the README,
-          # missing the prebuilt images in the Releases tab. Requiring a star (step 1
-          # of the README) reduces redundant builds — and runner costs — for images
-          # that may already exist in a recent forks list.
           FOUND=false
           PAGE=1
           while [ $PAGE -le 50 ]; do
@@ -64,15 +64,25 @@ jobs:
           done
 
           if [ "$FOUND" = "false" ]; then
+            echo "_build=false" >> $GITHUB_OUTPUT
             echo "## Before you build — check if someone already did it for you :point_down:" >> $GITHUB_STEP_SUMMARY
             echo "" >> $GITHUB_STEP_SUMMARY
             echo "Browse the **[Recent Forks List](https://github.com/LongQT-sea/mkmaciso/releases/latest)** — someone may have already built the macOS version you need." >> $GITHUB_STEP_SUMMARY
             echo "" >> $GITHUB_STEP_SUMMARY
-            echo "If you still need to build your own, star [the repo](https://github.com/LongQT-sea/mkmaciso) first — that's step 1 in the [README](https://github.com/LongQT-sea/macos-iso-builder#how-to-use). :star:" >> $GITHUB_STEP_SUMMARY
+            echo "Still need to build your own? Star [LongQT-sea/macos-iso-builder](https://github.com/LongQT-sea/macos-iso-builder), then re-run the workflow :star:" >> $GITHUB_STEP_SUMMARY
             echo "<br>![star](https://raw.githubusercontent.com/LongQT-sea/macos-iso-builder/main/.github/star.jpg)" >> $GITHUB_STEP_SUMMARY
-            exit 1
+            exit 0
           fi
 
+          echo "_build=true" >> $GITHUB_OUTPUT
+
+  build-macos-image:
+    needs: preflight
+    if: needs.preflight.outputs._build == 'true'
+    runs-on: macos-15-intel
+    timeout-minutes: 80
+
+    steps:
       - name: Checkout repository
         uses: actions/checkout@v6
 

.github/workflows/build-recovery.yml

@@ -24,25 +24,25 @@ on:
         type: string
 
 jobs:
-  build-recovery-iso:
+  preflight:
     if: ${{ inputs.macos_version != '' }}
-    runs-on: macos-latest
+    runs-on: ubuntu-slim
     permissions:
       contents: write  # needed to create releases
-    timeout-minutes: 15
+    timeout-minutes: 5
+    outputs:
+      _build: ${{ steps.check.outputs._build }}
 
     steps:
       - name: Preflight
+        id: check
         run: |
           # Third time's the charm
-          if [ "$GITHUB_RUN_ATTEMPT" -ge 2 ] || [ "$GITHUB_RUN_NUMBER" -ge 2 ]; then
+          if [ "$GITHUB_RUN_ATTEMPT" -ge 3 ] || [ "$GITHUB_RUN_NUMBER" -ge 3 ]; then
+            echo "_build=true" >> $GITHUB_OUTPUT
             exit 0
           fi
 
-          # Most users arrive directly at the Actions tab without reading the README,
-          # missing the prebuilt images in the Releases tab. Requiring a star (step 1
-          # of the README) reduces redundant builds — and runner costs — for images
-          # that may already exist in a recent forks list.
           FOUND=false
           PAGE=1
           while [ $PAGE -le 50 ]; do
@@ -56,15 +56,25 @@ jobs:
           done
 
           if [ "$FOUND" = "false" ]; then
+            echo "_build=false" >> $GITHUB_OUTPUT
             echo "## Before you build — check if someone already did it for you :point_down:" >> $GITHUB_STEP_SUMMARY
             echo "" >> $GITHUB_STEP_SUMMARY
             echo "Browse the **[Recent Forks List](https://github.com/LongQT-sea/mkmaciso/releases/latest)** — someone may have already built the macOS version you need." >> $GITHUB_STEP_SUMMARY
             echo "" >> $GITHUB_STEP_SUMMARY
-            echo "If you still need to build your own, star [the repo](https://github.com/LongQT-sea/mkmaciso) first — that's step 1 in the [README](https://github.com/LongQT-sea/macos-iso-builder#how-to-use). :star:" >> $GITHUB_STEP_SUMMARY
+            echo "Still need to build your own? Star [LongQT-sea/macos-iso-builder](https://github.com/LongQT-sea/macos-iso-builder), then re-run the workflow :star:" >> $GITHUB_STEP_SUMMARY
             echo "<br>![star](https://raw.githubusercontent.com/LongQT-sea/macos-iso-builder/main/.github/star.jpg)" >> $GITHUB_STEP_SUMMARY
-            exit 1
+            exit 0
           fi
 
+          echo "_build=true" >> $GITHUB_OUTPUT
+
+  build-recovery-iso:
+    needs: preflight
+    if: needs.preflight.outputs._build == 'true'
+    runs-on: macos-latest
+    timeout-minutes: 15
+
+    steps:
       - name: Checkout repository
         uses: actions/checkout@v6