aead.scm fails on Mac OS

I tried to build 65ebe54d, and it fails like this:

FAIL: tests/aead.scm
====================


throw to `gnutls-error' with args (#<gnutls-error-enum Decryption has failed.> aead-cipher-decrypt) [PID 88468]
FAIL tests/aead.scm (exit status: 1)

Any ideas? I'll try to narrow it down.