$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_with_macros.git /var/lib/mock/f40-build-2508010-61703/root/chroot_tmpdir/scmroot/rust-serde_with_macros
Cloning into '/var/lib/mock/f40-build-2508010-61703/root/chroot_tmpdir/scmroot/rust-serde_with_macros'...
$ git fetch origin 7bdeb67ba9933cf62e4dbb41aa28339863fe2425:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_with_macros
 * [new ref]         7bdeb67ba9933cf62e4dbb41aa28339863fe2425 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7bdeb67 Update to version 3.6.1; Fixes RHBZ#2262027