$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-datastructures.git /var/lib/mock/f40-build-2590597-62628/root/chroot_tmpdir/scmroot/gap-pkg-datastructures
Cloning into '/var/lib/mock/f40-build-2590597-62628/root/chroot_tmpdir/scmroot/gap-pkg-datastructures'...
$ git fetch origin fd675cb7dd53d638efc86492ef06caa953916335:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-datastructures
 * [new ref]         fd675cb7dd53d638efc86492ef06caa953916335 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fd675cb Rebuild for gap 4.13.0