$ git clone -n https://src.fedoraproject.org/rpms/rust-test-case-macros.git /var/lib/mock/f39-build-1913793-42881/root/chroot_tmpdir/scmroot/rust-test-case-macros
Cloning into '/var/lib/mock/f39-build-1913793-42881/root/chroot_tmpdir/scmroot/rust-test-case-macros'...
$ git fetch origin 3a1cd1893ef1f965c9eb50bfb93f0534c3102513:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-test-case-macros
 * [new ref]         3a1cd1893ef1f965c9eb50bfb93f0534c3102513 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3a1cd18 Update to version 3.2.1; Fixes RHBZ#2242770