$ git clone -n https://src.fedoraproject.org/rpms/calibre.git /var/lib/mock/f39-build-2467352-61444/root/chroot_tmpdir/scmroot/calibre
Cloning into '/var/lib/mock/f39-build-2467352-61444/root/chroot_tmpdir/scmroot/calibre'...
$ git fetch origin 8ad2c4a993f20c1e2714106f1b53bcc684923516:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calibre
 * [new ref]         8ad2c4a993f20c1e2714106f1b53bcc684923516 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8ad2c4a Rebuild (qt6)