$ git clone -n https://src.fedoraproject.org/rpms/rust-nix0.26.git /var/lib/mock/f38-build-side-42-init-devel-1407141-31274/root/chroot_tmpdir/scmroot/rust-nix0.26
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1407141-31274/root/chroot_tmpdir/scmroot/rust-nix0.26'...
$ git fetch origin 56dcd474d999c5dc391d176be3fbf02d83abc689:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-nix0.26
 * [new ref]         56dcd474d999c5dc391d176be3fbf02d83abc689 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 56dcd47 Initial import (nix 0.26 compat package)