$ git clone -n https://src.fedoraproject.org/rpms/mingw-poppler.git /var/lib/mock/f42-build-side-1-3502906-45979/root/chroot_tmpdir/scmroot/mingw-poppler
Cloning into '/var/lib/mock/f42-build-side-1-3502906-45979/root/chroot_tmpdir/scmroot/mingw-poppler'...
$ git fetch origin 5622a63ca78829638b4461a0a70514c13ac06db3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mingw-poppler
 * [new ref]         5622a63ca78829638b4461a0a70514c13ac06db3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5622a63 Remove accidentally committed file