CI: Lower cost/run to 40% of original cost

...mostly by reducing the number of macOS runners

(43 x Linux) -> (17 x Linux) [40% of original cost]

Author: davidfstr

.github/workflows/ci.yaml

@@ -28,6 +28,11 @@ on:
           - 'x86_64'
           # NOTE: Required for building the distribution artifact
           - 'universal2'
+      run_macos_asan_tests:
+        description: 'Run macOS Address Sanitizer tests'
+        required: false
+        default: false
+        type: boolean
       show_notarization_log:
         description: 'Show notarization log for macOS'
         required: false
@@ -49,10 +54,13 @@ env:
 #    because segfaults more common on macOS
 jobs:
 
+  # CAUTION: macOS runners cost 10x a Linux runner and 5x a Windows runner.
+  #          Keep the matrix small to avoid high costs.
   build-macos-asan:
+    # Only run this expensive job when explicitly requested or when building distribution artifacts
+    if: ${{ github.event.inputs.run_macos_asan_tests == 'true' || github.event.inputs.build_dist_artifact == 'true' }}
     strategy:
       matrix:
-        # NOTE: Test lots of Python versions to look for segfaults
         python-version:
           - "3.11.9"
       fail-fast: false
@@ -125,6 +133,8 @@ jobs:
         run: |
           crystal --test ${TEST_NAMES}
 
+  # CAUTION: macOS runners cost 10x a Linux runner and 5x a Windows runner.
+  #          Keep the matrix small to avoid high costs.
   build-macos:
     strategy:
       matrix:
@@ -136,16 +146,7 @@ jobs:
           #- macos-15  # ARM-based
         # Test the earliest supported Python version only
         python-version:
-          # Test earliest to latest Python versions supported by Crystal,
-          # on at least one OS.
-          # 
-          # NOTE: Testing all Python versions on Linux would be faster
-          #       than on macOS because Linux runners are faster than 
-          #       every other OS. However macOS is the second fastest OS,
-          #       and doesn't require precompiled wxPython .wgn files.
           - "3.11.9"
-          - "3.12.9"
-          - "3.13.5"
       fail-fast: false
     runs-on: ${{ matrix.os }}
     timeout-minutes: 31  # 150% of normal time: 21 min, as of 2025-07-21
@@ -465,7 +466,16 @@ jobs:
           # NOTE: Earliest Windows supported by Crystal is Windows 11 (from the README)
           - windows-2025  # based on Windows 11 version 24H2 (Germanium)
         python-version:
+          # Test earliest to latest Python versions supported by Crystal,
+          # on at least one OS.
+          # 
+          # NOTE: Testing all Python versions on Linux would be faster
+          #       than on Windows because Linux runners are faster than 
+          #       every other OS. However Windows is the second fastest OS,
+          #       and doesn't require precompiled wxPython .wgn files.
           - "3.11.9"
+          - "3.12.9"
+          - "3.13.5"
       fail-fast: false
     runs-on: ${{ matrix.os }}
     timeout-minutes: 43  # 150% of normal time: 29 min, as of 2025-07-21

RELEASE_NOTES.md

@@ -64,6 +64,7 @@ and new `--port`/`--host` options for controlling how projects are served.
 * Development improvements
     * GitHub Copilot Agent now has a comprehensive set of AI instructions
       to refer to when making autonomous changes to Crystal.
+    * Decrease average cost of CI runs by running fewer macOS jobs by default.
 
 ### v1.10.0 (June 21, 2025)
 

poetry.lock

@@ -57,7 +57,7 @@ order_by_type = false  # don't sort constants specially
 crystal = 'crystal.__main__:main'
 
 [tool.poetry.dependencies]
-# NOTE: Python 3.11 is the latest Python supported by py2exe 0.13.0.2
+# NOTE: Python 3.13 is the latest Python supported by py2exe 0.14.0.0
 python = ">=3.11,<3.14"
 # NOTE: When changing the version of wxPython to Y, you'll need to make sure
 #       there is a precompiled wheel for {Python 3.X, wxPython Y, OS}
@@ -69,9 +69,8 @@ python = ">=3.11,<3.14"
 wxPython = "4.2.3"
 beautifulsoup4 = "^4.9.3"
 py2app = { version = "^0.28", markers = "sys_platform == 'darwin'" }
-# NOTE: py2exe 0.13.0.2 only supports Python 3.11, so we use a marker to
-#       ensure it is only installed on Windows with Python 3.11.
-py2exe = { version = "^0.13.0.2", markers = "sys_platform == 'win32' and python_version >= '3.11' and python_version < '3.12'" }
+# NOTE: py2exe 0.14.0.0 supports Python 3.11, 3.12, and 3.13.
+py2exe = { version = "^0.14.0.0", markers = "sys_platform == 'win32' and python_version >= '3.11'" }
 tinycss2 = "^1.1.0"
 appdirs = "^1.4.4"
 colorama = "^0.4.4"