$ git clone -n https://src.fedoraproject.org/rpms/mupdf.git /var/lib/mock/f41-build-856593-167686/root/chroot_tmpdir/scmroot/mupdf
Cloning into '/var/lib/mock/f41-build-856593-167686/root/chroot_tmpdir/scmroot/mupdf'...
$ git fetch origin 8cdac9f368ac50206300749e69a51097def8a1af:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mupdf
 * [new ref]         8cdac9f368ac50206300749e69a51097def8a1af -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8cdac9f Rebuild for tesseract-5.4.1-3 (soversion change from 5.4.1 to just 5.4)