Checking python in PATH is the one cibuildwheel installed/expects

[YannickJadoul]

Fixes #261

[YannickJadoul]

Once tests pass, two more things to consider:

• Should we resolve the symlinks with os.path.realpath?
• Should we throw an exception and/or print an error message? The main problem is that throwing a Python exception from the bash script in manylinux is not that easy...

[joerick]

This looks good to me. Probably worth adding an error message to save people raising issues. How about

cibuildwheel: python / pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python/pip above it.

[YannickJadoul]

This looks good to me. Probably worth adding an error message to save people raising issues. How about

cibuildwheel: python / pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python/pip above it.

Sure, sounds good. But just print it before test or assert, have it as the assert message, throw an exception, ...?

[joerick]

Whatever's convenient - assert message or just a simple print would be fine. As you mentioned, getting an exception out of the Linux script is hard, so echo error message; exit 1 might be the easiest. Or, I guess you could use a special return code from the bash script, if you wanted to get fancy! Up to you

[YannickJadoul]

(currently waiting to do this until the build gets fixed; see #270)

[YannickJadoul]

@joerick OK, ready for further review/merge, I think. Though it's probably best if this gets rebased onto #185, rather than the other way around.

[joerick]

Great. I'll let you decide the order you want to merge @YannickJadoul

[YannickJadoul]

@Czaki If you still want to have a quick look, I'll wait before merging this. (Not sure there is a lot to see, though. It's a pretty small PR. But still, if you spot something, do tell.)

[Czaki]

Tomorrow.

[YannickJadoul]

Tomorrow.

Great; no rush to get this merged!

[YannickJadoul]

Thanks, @Czaki! :-)