$ git clone -n https://src.fedoraproject.org/rpms/rust-proc-macro-crate.git /var/lib/mock/f39-build-2249931-54022/root/chroot_tmpdir/scmroot/rust-proc-macro-crate
Cloning into '/var/lib/mock/f39-build-2249931-54022/root/chroot_tmpdir/scmroot/rust-proc-macro-crate'...
$ git fetch origin 94b25cf59029ac12fd84e71b8f989df808a22f39:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-proc-macro-crate
 * [new ref]         94b25cf59029ac12fd84e71b8f989df808a22f39 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 94b25cf Update to version 2.0.1