Refactor MacOS CI Builds

- move the bootstrapping of MacOS into a script so it's easier to
  see what is going on and customize it for the various MacOS
  releases

.github/workflows/macos-ci.yml

@@ -27,44 +27,31 @@ jobs:
         compiler:
           - clang
           - gcc
-        homebrew-gl:
-          - true
-          # - false
-        homebrew-al:
-          - true
-          - false
 
     steps:
 
       # The following dependencies are already present within macos-* images:
-      # - clang (llvm)
-      # - cmake
-      # - expat
-      # - gcc
-      # - git
-      # - jpeg
-      # - libpng
-      # - libvorbis
-      # - python
-      - name: Install dependencies using homebrew
-        run: brew install boost-python3 gtk+3 gtkglext sdl
+      # MacOS has a Developers Tools package from Apple that gets installed which
+      # provides some minimal functionality:
+      #   XCode (which uses CLang/LLVM)
+      #   git
+      - name: Install Base tooling via homebrew
+        run: brew install bash shtool
 
-      # The following Apple-provided libraries are deprecated:
-      # * OpenGL as of macOS 10.14
-      # * GLUT as of macOS 10.9
-      - name: Optionally install homebrewed OpenGL and GLUT
-        if: ${{ matrix.homebrew-gl }}
-        run: |
-          brew install mesa mesa-glu freeglut
-          ln -s /usr/local/include/GL /usr/local/include/OpenGL
-          ln -s /usr/local/include/GL /usr/local/include/GLUT
-        # ln -s /usr/local/lib/libGL.dylib /usr/local/lib/libOpenGL.dylib
-        # find /usr/local/lib/ -iname '*gl*.dylib'
+      - name: Bootstrap MacOS
+        run: script/bootstrap-mac.sh
 
-      # The Apple-provided OpenAL is deprecated as of macOS 10.15
-      - name: Optionally install homebrewed OpenAL
-        if: ${{ matrix.homebrew-al }}
-        run: brew install openal-soft
+      - name: Install dependencies using homebrew
+        run: brew install \
+            gcc \
+            cmake \
+            python3 \
+            boost-python3 \
+            jpeg \
+            libpng \
+            gtk+3 \
+            gtkglext \
+            sdl2 \
 
       - name: Check out repository
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 #v4.1.1
@@ -77,6 +64,8 @@ jobs:
         if: github.event.pull_request
         run: git checkout HEAD^2
 
+      # Note: it might be good to use a step to detect where OpenAL-Soft is
+      # installed and set it to a GHA variable that can be consumed below
       - name: Build it
         env:
           MY_OS_NAME: macos

script/bootstrap-mac.sh

@@ -0,0 +1,69 @@
+#!/opt/homebrew/bin/bash
+set -e
+
+DETECT_MAC_OS_VERSION=$(sw_vers -productVersion | cut -f 1,2 -d '.')
+echo "Detected Mac OS X Version: ${DETECT_MAC_OS_VERSION}"
+
+MAC_OS_NAME="UNKOWN"
+case "${DETECT_MAC_OS_VERSION}" in
+    "10.13")
+        MAC_OS_NAME="High_Sierra"
+        ;;
+    "10.14")
+        MAC_OS_NAME="Mojave"
+        ;;
+    "10.15")
+        MAC_OS_NAME="Catalina"
+        ;;
+    "11.*")
+        MAC_OS_NAME="Big_Sur"
+        ;;
+    "12.*")
+        MAC_OS_NAME="Monterey"
+        ;;
+    "13.*")
+        MAC_OS_NAME="Ventura"
+        ;;
+    "14.*")
+        MAC_OS_NAME="Sonoma"
+        ;;
+    "15.*")
+        MAC_OS_NAME="Sequoia"
+        ;;
+    *)
+        echo "Unknown Mac Release: ${DETECT_MAC_OS_VERSION}"
+        exit 1
+        ;;
+esac
+
+echo "Detected Mac OS X ${DETECT_MAC_OS_VERSION} - ${MAC_OS_NAME}"
+# While we may be able to assume some other dependencies there does seem to be
+# some changes between versions of MacOS on which are provided by default; so
+# aside from the two above we should just go ahead an install everything ourselves.
+
+# Install the stuff we know needs to get installed all the time
+brew install \
+    gcc \
+    cmake \
+    python3 \
+    boost-python3 \
+    jpeg \
+    libpng \
+    gtk+3 \
+    gtkglext \
+    sdl2
+
+# The following Apple-provided libraries are deprecated:
+# * OpenGL as of macOS 10.14
+# * GLUT as of macOS 10.9
+brew install mesa mesa-glu freeglut
+ln -s /usr/local/include/GL /usr/local/include/OpenGL
+ln -s /usr/local/include/GL /usr/local/include/GLUT
+# ln -s /usr/local/lib/libGL.dylib /usr/local/lib/libOpenGL.dylib
+# find /usr/local/lib/ -iname '*gl*.dylib'
+
+# MacOS 13+ needs Vorbis support
+brew install vorbis-tools
+
+# The Apple-provided OpenAL is deprecated as of macOS 10.15
+brew install openal-soft freealut