I have not set up git-send-email yet, but here is a patch to remove the set-PATH_MAX phase as it prevents the package from building, misc/tune2fs.c now #defines' PATH_MAX  itself if it missing.

Successfully build the package with offloading to a childhurd.
/gnu/store/wvbmfvhbhh6bwx67rwa2dfzslx5j0gv6-e2fsprogs-1.47.1