$ git clone -n https://src.fedoraproject.org/rpms/libidn.git /var/lib/mock/f45-build-39877-764/root/chroot_tmpdir/scmroot/libidn
Cloning into '/var/lib/mock/f45-build-39877-764/root/chroot_tmpdir/scmroot/libidn'...
$ git fetch origin 223e65c364e582f92c5e6d4a8050109865547c96:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libidn
 * [new ref]         223e65c364e582f92c5e6d4a8050109865547c96 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 223e65c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild