$ git clone -n https://src.fedoraproject.org/rpms/rust-regex.git /var/lib/mock/f40-build-1924441-25102/root/chroot_tmpdir/scmroot/rust-regex
Cloning into '/var/lib/mock/f40-build-1924441-25102/root/chroot_tmpdir/scmroot/rust-regex'...
$ git fetch origin 7060365f65b35803aeaada722716b8245d21783b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-regex
 * [new ref]         7060365f65b35803aeaada722716b8245d21783b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7060365 Update to version 1.10.6; Fixes RHBZ#2302521