rpath's sanity check crashes when building numpy

[pescobar]

while doing my first test with rpath I have found that the sanity check in rpath crashes when building numpy. This is the error message:

AttributeError: 'EB_numpy' object has no attribute 'modules_tool'

This is the full debug log:
https://gist.github.com/anonymous/41ce31fd5419b76a3a9b03135adc1578

[pescobar]

in case this makes any difference, I am not getting this error when building a numpy easyconfig. I get the error when building a python easyconfig which includes numpy in the extensions list.

[boegel]

@pescobar it does make a difference, EB_numpy inherits both from EasyBlock and Extension, and apparently in the latter case something is broken, but only when --rpath is used, which is kind of weird...

[boegel]

fixed in #2026, kind of a silly bug...