$ git clone -n https://src.fedoraproject.org/rpms/subnetcalc.git /var/lib/mock/f40-build-2645721-66584/root/chroot_tmpdir/scmroot/subnetcalc
Cloning into '/var/lib/mock/f40-build-2645721-66584/root/chroot_tmpdir/scmroot/subnetcalc'...
$ git fetch origin 2b5a22c78b8e2d1b8577f478717730e5bf0b54be:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/subnetcalc
 * [new ref]         2b5a22c78b8e2d1b8577f478717730e5bf0b54be -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2b5a22c SPDX migration