GitHub: Build MSYS2 commit SHA

The PKGBUILD always builds the tip of the master branch. Try to
allow selecting a commit using $PKG_COMMIT.

.github/workflows/msys2.yml

@@ -16,9 +16,11 @@ jobs:
           update: true
           install: base-devel
       - name: Build
+        env:
+          PKG_COMMIT: ${{ github.sha }}
         run: |
           mkdir build && cd build
-          wget "https://raw.githubusercontent.com/wireshark/wireshark/$GITHUB_SHA/packaging/msys2/mingw-w64-wireshark-git/PKGBUILD"
+          wget "https://raw.githubusercontent.com/wireshark/wireshark/${PKG_COMMIT}/packaging/msys2/mingw-w64-wireshark-git/PKGBUILD"
           makepkg-mingw --cleanbuild --syncdeps --force --install --noconfirm
       - name: Show version
         run: |

packaging/msys2/mingw-w64-wireshark-git/PKGBUILD

@@ -45,13 +45,14 @@ makedepends=("${MINGW_PACKAGE_PREFIX}-cmake"
              'git')
 provides=("${MINGW_PACKAGE_PREFIX}-${_realname}")
 conflicts=("${MINGW_PACKAGE_PREFIX}-${_realname}")
-source=("${_realname}"::"git+https://gitlab.com/wireshark/wireshark.git")
+_commit=${PKG_COMMIT:-HEAD}
+source=("${_realname}"::"git+https://gitlab.com/wireshark/wireshark.git#commit=${_commit}")
 sha256sums=('SKIP')
 
 pkgver() {
   cd "${_realname}"
 
-  git describe --long | sed 's/^v//;s/\([^-]*-g\)/r\1/;s/-/./g;s/^v//g'
+  git describe --long "${_commit}" | sed 's/^v//;s/\([^-]*-g\)/r\1/;s/-/./g;s/^v//g'
 }
 
 build() {