I’m trying to get PyMetrics set up, to help find places in my codebase that need more testing.

During the build, I get errors like this:

pymetrics-0.8.1$ python setup.py build
running build
running build_py
running build_scripts
error: Is a directory

This is a very peculiar error message to receive. A little bit of digging into setup.py reveals the (unlikely) answer:

       packages = ['PyMetrics'],
       scripts = ['pymetrics']

Looks like the build file is trying to make a package directory called “PyMetrics”, and a script called “pymetrics”. That’s OK on every other Unix derivative, but for some reason, HFS on OS X comes by default to use a case-insensitive filesystem. This means that those two files can’t actually co-exist.

Bah!