$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-digraphs.git /var/lib/mock/f39-build-1506492-35195/root/chroot_tmpdir/scmroot/gap-pkg-digraphs
Cloning into '/var/lib/mock/f39-build-1506492-35195/root/chroot_tmpdir/scmroot/gap-pkg-digraphs'...
$ git fetch origin ad4c005f04a5443964137d5c7fc218b4e02aec4d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-digraphs
 * [new ref]         ad4c005f04a5443964137d5c7fc218b4e02aec4d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ad4c005 Version 1.6.3