$ git clone -n https://src.fedoraproject.org/rpms/rust-gvdb-macros.git /var/lib/mock/f40-build-2248643-53956/root/chroot_tmpdir/scmroot/rust-gvdb-macros
Cloning into '/var/lib/mock/f40-build-2248643-53956/root/chroot_tmpdir/scmroot/rust-gvdb-macros'...
$ git fetch origin 7398492e0133ce1d4758ab95870dbaa0e7a13a95:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gvdb-macros
 * [new ref]         7398492e0133ce1d4758ab95870dbaa0e7a13a95 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7398492 Update to version 0.1.11; Fixes RHBZ#2252595