sha256 hash mismatch for /gnu/store/5hkf0xjga0wirk1wv8fsqvyazai4zzh6-foo2zjs.tar.gz:
  expected hash: 11ddx6wf8b5ksl4fqw6fnyz9m3y470lryyrskkya2bsch2bvj9lg
  actual hash:   14x3wizvncdy0xgvmcx541qanwb7bg76abygqy17bxycn1zh5r1x
hash mismatch for store item '/gnu/store/5hkf0xjga0wirk1wv8fsqvyazai4zzh6-foo2zjs.tar.gz'
build of /gnu/store/4b4fq6j1zwffz8l8c69b6y3lj2ixdl8c-foo2zjs.tar.gz.drv failed

That's because http://foo2zjs.rkkda.com/foo2zjs.tar.gz is not versioned, and we
use that anyway.  WTF?