Make check fails against master with "Trace/BPT trap ${dir}$tst" on OSX

[Shea Levy]

Hello all,

The continuous build system at 
http://hydra.nixos.org/jobset/gnu/libidn-master fails to successfully 
build rev 5f79ec02b76ed7f552d875a38a9915d5b4f977dc on OSX due to all 12 
tests failing. Each test fails with a message along the lines of 
"/bin/sh: line 5: 19600 Trace/BPT trap          ${dir}$tst", see the 
bottom of http://hydra.nixos.org/build/1559609/log/raw for the exact 
messages.

Cheers,
Shea Levy