insert the commit SHA in Windows binary releases

the Windows release task does not checkout the
F* repository with the git command, but rather
with the GitHub REST API, so we need to get
the commit hash from outside

.github/workflows/release.yml

@@ -67,6 +67,6 @@ jobs:
     - name: Package and release FStar
       shell: C:\cygwin64\bin\bash.exe --login '{0}'
       run: |
-        CI_THREADS=24 $GITHUB_WORKSPACE/.scripts/release.sh && echo "There is a CR at the end of this line"
+        FSTAR_COMMIT=$GITHUB_SHA CI_THREADS=24 $GITHUB_WORKSPACE/.scripts/release.sh && echo "There is a CR at the end of this line"
       env:
         GH_TOKEN: ${{ secrets.DZOMO_GITHUB_TOKEN }}

ocaml/fstar-lib/make_fstar_version.sh

@@ -14,7 +14,9 @@ else
 fi
 COMPILER="OCaml $(ocamlc -version)"
 # If a system does not have git, or we are not in a git repo, fallback with "unset"
-COMMIT=$(git describe --match="" --always --abbrev=40 --dirty 2>/dev/null || echo unset)
+if [[ -z "$FSTAR_COMMIT" ]] ; then
+   FSTAR_COMMIT=$(git describe --match="" --always --abbrev=40 --dirty 2>/dev/null || echo unset)
+fi
 COMMITDATE=$(git log --pretty=format:%ci -n 1 2>/dev/null || echo unset)
 
 echo "let dummy () = ();;"
@@ -23,4 +25,4 @@ echo "FStar_Options._platform := \"$PLATFORM\";;"
 echo "FStar_Options._compiler := \"$COMPILER\";;"
 # We deliberately use commitdate instead of date, so that rebuilds are no-ops
 echo "FStar_Options._date := \"$COMMITDATE\";;"
-echo "FStar_Options._commit:= \"$COMMIT\";;"
+echo "FStar_Options._commit:= \"$FSTAR_COMMIT\";;"