$ git clone -n https://src.fedoraproject.org/rpms/rust-linreg.git /var/lib/mock/f45-build-43015-799/root/chroot_tmpdir/scmroot/rust-linreg
Cloning into '/var/lib/mock/f45-build-43015-799/root/chroot_tmpdir/scmroot/rust-linreg'...
$ git fetch origin fe1ab77d292484749c5b5f5a2498b99022844487:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-linreg
 * [new ref]         fe1ab77d292484749c5b5f5a2498b99022844487 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fe1ab77 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild