$ git clone -n https://src.fedoraproject.org/rpms/ghc-gi-gobject.git /var/lib/mock/f40-build-1932293-25124/root/chroot_tmpdir/scmroot/ghc-gi-gobject
Cloning into '/var/lib/mock/f40-build-1932293-25124/root/chroot_tmpdir/scmroot/ghc-gi-gobject'...
$ git fetch origin b883f69f82d12dece11792ee486bae2619228dc6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-gi-gobject
 * [new ref]         b883f69f82d12dece11792ee486bae2619228dc6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b883f69 Add a temporary override to CFLAGS