$ git clone -n https://src.fedoraproject.org/rpms/rust-which.git /var/lib/mock/f39-build-2329452-58921/root/chroot_tmpdir/scmroot/rust-which
Cloning into '/var/lib/mock/f39-build-2329452-58921/root/chroot_tmpdir/scmroot/rust-which'...
$ git fetch origin 8de3009b7fe6d2584de73c30a8ac6234c7c342de:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-which
 * [new ref]         8de3009b7fe6d2584de73c30a8ac6234c7c342de -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8de3009 Update to version 5.0.0