$ git clone -n https://src.fedoraproject.org/rpms/porcupine.git /var/lib/mock/f41-build-side-2-python-2735873-30832/root/chroot_tmpdir/scmroot/porcupine
Cloning into '/var/lib/mock/f41-build-side-2-python-2735873-30832/root/chroot_tmpdir/scmroot/porcupine'...
$ git fetch origin aa5d0f1427525c1f1b3bfa5c7b557ff9b69402fe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/porcupine
 * [new ref]         aa5d0f1427525c1f1b3bfa5c7b557ff9b69402fe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aa5d0f1 convert license to SPDX