$ git clone -n https://src.fedoraproject.org/rpms/rust-derive_builder_macro.git /var/lib/mock/f41-build-side-1-2757608-31454/root/chroot_tmpdir/scmroot/rust-derive_builder_macro
Cloning into '/var/lib/mock/f41-build-side-1-2757608-31454/root/chroot_tmpdir/scmroot/rust-derive_builder_macro'...
$ git fetch origin 255e1b5f0df43613e21818b8b283ccb65b9d3681:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-derive_builder_macro
 * [new ref]         255e1b5f0df43613e21818b8b283ccb65b9d3681 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 255e1b5 Update to version 0.20.1; Fixes RHBZ#2309036