$ git clone -n https://src.fedoraproject.org/rpms/rust-regex-syntax0.7.git /var/lib/mock/f41-build-1283274-23209/root/chroot_tmpdir/scmroot/rust-regex-syntax0.7
Cloning into '/var/lib/mock/f41-build-1283274-23209/root/chroot_tmpdir/scmroot/rust-regex-syntax0.7'...
$ git fetch origin c6a0393fd8bf45e5b503499c04184c00f97d4c25:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-regex-syntax0.7
 * [new ref]         c6a0393fd8bf45e5b503499c04184c00f97d4c25 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c6a0393 compat package no longer needed