$ git clone -n https://src.fedoraproject.org/rpms/rust-regex-lite.git /var/lib/mock/f39-build-1508996-35421/root/chroot_tmpdir/scmroot/rust-regex-lite
Cloning into '/var/lib/mock/f39-build-1508996-35421/root/chroot_tmpdir/scmroot/rust-regex-lite'...
$ git fetch origin 6200f5aba779c68f9bf953f2e287af002866da90:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-regex-lite
 * [new ref]         6200f5aba779c68f9bf953f2e287af002866da90 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6200f5a Update to version 0.1.5; Fixes RHBZ#2244295