$ git clone -n https://src.fedoraproject.org/rpms/rust-scientific-macro.git /var/lib/mock/f45-build-44703-816/root/chroot_tmpdir/scmroot/rust-scientific-macro
Cloning into '/var/lib/mock/f45-build-44703-816/root/chroot_tmpdir/scmroot/rust-scientific-macro'...
$ git fetch origin 062bff1f646765163ff7274aa7286c5cf4ed69a5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-scientific-macro
 * [new ref]         062bff1f646765163ff7274aa7286c5cf4ed69a5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 062bff1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild