$ git clone -n https://src.fedoraproject.org/rpms/rust-regex-syntax.git /var/lib/mock/f38-build-side-43-rust-devel-1410746-31421/root/chroot_tmpdir/scmroot/rust-regex-syntax
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1410746-31421/root/chroot_tmpdir/scmroot/rust-regex-syntax'...
$ git fetch origin c2cda43fb7712dade25558e618d5cfba2c6d6b63:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-regex-syntax
 * [new ref]         c2cda43fb7712dade25558e618d5cfba2c6d6b63 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c2cda43 Update to version 0.8.2; Fixes RHBZ#2242957