$ git clone -n https://src.fedoraproject.org/rpms/calibre.git /var/lib/mock/f41-build-2441661-25470/root/chroot_tmpdir/scmroot/calibre
Cloning into '/var/lib/mock/f41-build-2441661-25470/root/chroot_tmpdir/scmroot/calibre'...
$ git fetch origin f340038ecd28fcad562ab0cce5e148eeecbd224e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calibre
 * [new ref]         f340038ecd28fcad562ab0cce5e148eeecbd224e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f340038 Fix font conditionals to handle f40 and older correctly