$ git clone -n https://src.fedoraproject.org/rpms/rust-tokio-current-thread.git /var/lib/mock/f41-build-side-1-3129194-39576/root/chroot_tmpdir/scmroot/rust-tokio-current-thread
Cloning into '/var/lib/mock/f41-build-side-1-3129194-39576/root/chroot_tmpdir/scmroot/rust-tokio-current-thread'...
$ git fetch origin 473788a6f955745437ea842ff1a324870ce6bcf0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tokio-current-thread
 * [new ref]         473788a6f955745437ea842ff1a324870ce6bcf0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 473788a no longer needed