$ git clone -n https://src.fedoraproject.org/rpms/perl-Image-Size.git /var/lib/mock/f41-build-780075-13558/root/chroot_tmpdir/scmroot/perl-Image-Size
Cloning into '/var/lib/mock/f41-build-780075-13558/root/chroot_tmpdir/scmroot/perl-Image-Size'...
$ git fetch origin f029486ad14eb86b62a23f46fe630af7a876e016:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Image-Size
 * [new ref]         f029486ad14eb86b62a23f46fe630af7a876e016 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f029486 Eliminate use of obsolete %patchN syntax (#2283636)