fix: Fix builds in latest GitHub environments (#18)

This fixes several (but not quite all) issues with building in GitHub
Actions environments:

- macOS: Unlink additional conflicting libraries now installed by
default through homebrew
- Windows: Install msys tools that _used_ to be installed by default,
but now need msys versions to be explicitly installed
- Windows: Drop gcc from update list to avoid hanging while installing
packages (not sure why this works)
 - Linux: Fix location of libaom pkg-config file
- All: Upload artifacts before checking them, so that the binaries can
be debugged if they fail a later check

Remaining issues:
- FFmpeg build can't find libaom on Windows... but I plan to remove aom
shortly.

.github/workflows/build.yaml

@@ -145,12 +145,25 @@ jobs:
  # static library builds below. They are still installed, but will no
  # longer be symlinked into default library paths, and the ffmpeg
  # build will not pick up pre-installed shared libraries we don't want.
- # Only our static versions will be used.
- brew unlink \
+ # Only our static versions will be used. The list of preinstalled
+ # packages in the GitHub Actions environment may change over time, so
+ # this list may need to change, as well. Ignore errors if one of
+ # these is not installed.
+ for i in \
+ aom \
  lame \
+ libvpx \
+ libxau \
+ libxcb \
+ libxdmcp \
+ mbedtls \
  opus \
  opusfile \
- xz
+ svt-av1 \
+ x264 \
+ x265 \
+ xz \
+ ; do brew unlink $i || true; done
 
  # Use sudo in install commands on macOS.
  echo "SUDO=sudo" >> "$GITHUB_ENV"
@@ -171,8 +184,16 @@ jobs:
  set -x
 
  # Install msys packages we will need.
+ # NOTE: Add tools to this list if you see errors like
+ # "shared_info::initialize: size of shared memory region changed".
+ # The tools reporting such errors need to be explicitly replaced by
+ # msys versions. The list of preinstalled packages in the GitHub
+ # Actions environment may change over time, so this list may need to
+ # change, as well.
  pacman -Sy --noconfirm \
+ diffutils \
  git \
+ make \
  mercurial \
  nasm \
  yasm
@@ -221,8 +242,12 @@ jobs:
 
  # NOTE: without CMAKE_INSTALL_PREFIX on Windows, files are installed
  # to c:\Program Files.
+ # NOTE: without CMAKE_INSTALL_LIBDIR on Linux, pkgconfig and static
+ # libs are installed to /usr/local/lib/x86_64-linux-gnu/ instead of
+ # /usr/local/lib/.
  cmake ../aom \
  -DCMAKE_INSTALL_PREFIX=/usr/local \
+ -DCMAKE_INSTALL_LIBDIR=lib \
  -DENABLE_DOCS=OFF \
  -DENABLE_EXAMPLES=OFF \
  -DENABLE_TESTS=OFF \
@@ -348,6 +373,7 @@ jobs:
  # This flag is needed when building on Windows.
  if [[ "${{ runner.os }}" == "Windows" ]]; then
  export WINDOWS_BUILD=1
+ export CC=gcc
  fi
 
  # NOTE: The library is built statically unless SHARED environment
@@ -418,6 +444,31 @@ jobs:
  make
  # No "make install" for ffmpeg.
 
+ - name: Prepare assets
+ run: |
+ set -e
+ set -x
+
+ mkdir assets
+ SUFFIX="-${{ matrix.os_name }}-${{ matrix.target_arch }}${{ matrix.exe_ext}}"
+ echo "SUFFIX=$SUFFIX" >> "$GITHUB_ENV"
+ cp ffmpeg/ffmpeg assets/ffmpeg"$SUFFIX"
+ cp ffmpeg/ffprobe assets/ffprobe"$SUFFIX"
+
+ # Show sizes and MD5 sums that can be verified by users later if they
+ # want to check for authenticity.
+ cd assets
+ wc -c *
+ md5sum *
+
+ # This makes it possible to debug failures in the next step by
+ # downloading binaries that fail the check for static linkage.
+ - name: Upload assets as artifacts
+ uses: actions/upload-artifact@v3
+ with:
+ name: binaries${{ env.SUFFIX }}
+ path: assets/*
+
  - name: Check that executables are static
  run: |
  set -e
@@ -451,22 +502,6 @@ jobs:
  # to make this step of the workflow a success.
  true
 
- - name: Prepare assets
- run: |
- set -e
- set -x
-
- mkdir assets
- SUFFIX="-${{ matrix.os_name }}-${{ matrix.target_arch }}${{ matrix.exe_ext}}"
- cp ffmpeg/ffmpeg assets/ffmpeg"$SUFFIX"
- cp ffmpeg/ffprobe assets/ffprobe"$SUFFIX"
-
- # Show sizes and MD5 sums that can be verified by users later if they
- # want to check for authenticity.
- cd assets
- wc -c *
- md5sum *
-
  - name: Attach assets to release
  if: inputs.release_id != ''
  env: