$ git clone -n https://src.fedoraproject.org/rpms/libwnck3.git /var/lib/mock/f42-build-side-1-3588270-46944/root/chroot_tmpdir/scmroot/libwnck3
Cloning into '/var/lib/mock/f42-build-side-1-3588270-46944/root/chroot_tmpdir/scmroot/libwnck3'...
$ git fetch origin 85c90aed23236f8e08c982bd5b81bf1b071fca49:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libwnck3
 * [new ref]         85c90aed23236f8e08c982bd5b81bf1b071fca49 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 85c90ae Convert to %autorelease and %autochangelog