$ git clone -n https://github.com/fedora-riscv/mozjs102.git /var/lib/mock/f38-build-side-42-init-devel-612949-26292/root/chroot_tmpdir/scmroot/mozjs102
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-612949-26292/root/chroot_tmpdir/scmroot/mozjs102'...
$ git fetch origin 21e4867efea92a36ae7bdcf295235493c6b22a60:KOJI_FETCH_HEAD
From https://github.com/fedora-riscv/mozjs102
 * [new ref]         21e4867efea92a36ae7bdcf295235493c6b22a60 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21e4867 Merge remote-tracking branch 'fedoraproject/f38' into f38-rv64