This is with master (#6e14e62). Here is the `--debug` output:
```
00:00.005 018434 SYSTEM locking /home/greg/.opam/lock
00:00.006 018434 FILE(config) R…
I got this build failure with ocaml-3.11.2 on MacOS X when trying to compile froc without ocamljs (I'm just installing that now too, but thought you might want to know about this).
```
./configure -d…