release: include GIT_BUILT_FROM_COMMIT in MacOS build

Set the `GIT_BUILT_FROM_COMMIT` based on the version specified in the `make
dist` output archive header. This ensures the commit hash is shown in
`git version --build-options`.

Signed-off-by: Victoria Dye <vdye@github.com>

.github/macos-installer/Makefile

@@ -21,7 +21,7 @@ GIT_PREFIX := $(PREFIX)/git
 BUILD_DIR := $(GITHUB_WORKSPACE)/payload
 DESTDIR := $(PWD)/stage/git-$(ARCH_UNIV)-$(VERSION)
 ARTIFACTDIR := build-artifacts
-SUBMAKE := $(MAKE) C_INCLUDE_PATH="$(C_INCLUDE_PATH)" CPLUS_INCLUDE_PATH="$(CPLUS_INCLUDE_PATH)" LD_LIBRARY_PATH="$(LD_LIBRARY_PATH)" TARGET_FLAGS="$(TARGET_FLAGS)" CFLAGS="$(CFLAGS)" LDFLAGS="$(LDFLAGS)" NO_GETTEXT=1 NO_DARWIN_PORTS=1 prefix=$(GIT_PREFIX) DESTDIR=$(DESTDIR)
+SUBMAKE := $(MAKE) C_INCLUDE_PATH="$(C_INCLUDE_PATH)" CPLUS_INCLUDE_PATH="$(CPLUS_INCLUDE_PATH)" LD_LIBRARY_PATH="$(LD_LIBRARY_PATH)" TARGET_FLAGS="$(TARGET_FLAGS)" CFLAGS="$(CFLAGS)" LDFLAGS="$(LDFLAGS)" NO_GETTEXT=1 NO_DARWIN_PORTS=1 prefix=$(GIT_PREFIX) GIT_BUILT_FROM_COMMIT="$(GIT_BUILT_FROM_COMMIT)" DESTDIR=$(DESTDIR)
 CORES := $(shell bash -c "sysctl hw.ncpu | awk '{print \$$2}'")
 
 # Guard against environment variables

.github/workflows/build-git-installers.yml

@@ -428,6 +428,9 @@ jobs:
 
           make -C git -j$(sysctl -n hw.physicalcpu) GIT-VERSION-FILE dist dist-doc
 
+          export GIT_BUILT_FROM_COMMIT=$(gunzip -c git/git-$VERSION.tar.gz | git get-tar-commit-id) ||
+            die "Could not determine commit for build"
+
           # Extract tarballs
           mkdir payload manpages
           tar -xvf git/git-$VERSION.tar.gz -C payload