Autotester FreeBSD: Cycle detected between modules with ctors/dtors

[via Digitalmars-d]

The autotester complains about cycles between module ctors on 
FreeBSD 32/64 for this PR:
https://github.com/D-Programming-Language/phobos/pull/3233

The modules are std.digest.hmac (added in the PR), and 
std.digest.digest. However, neither of them even has a module 
ctor or dtor.

I remember vaguely that there were some problems with cycle 
detection. Is this an instance of it? What can be done about it?