Cvxpy: RuntimeError with numpy 1.16

[skoudoro]

Hi CVXPY Team,

As you can see here, our build bots generate the following error:

Traceback (most recent call last):
  File "/home/travis/build/nipy/dipy/venv/lib/python3.5/site-packages/cvxpy/cvxcore/python/cvxcore.py", line 18, in swig_import_helper
    fp, pathname, description = imp.find_module('_cvxcore', [dirname(__file__)])
  File "/home/travis/build/nipy/dipy/venv/lib/python3.5/imp.py", line 297, in find_module
    raise ImportError(_ERR_MSG.format(name), name=name)
ImportError: No module named '_cvxcore'
During handling of the above exception, another exception occurred:

RuntimeError: module compiled against API version 0xd but this version of numpy is 0xc

cvxpy is built with numpy-1.16.0.dev0+977431a

How can I fix that? Did I do something wrong?

Thanks

[rileyjmurray]

Small, initial comment:

From time to time we do get issues with importing cvxcore (https://github.com/cvxgrp/cvxpy/issues?utf8=%E2%9C%93&q=is%3Aissue+ImportError%3A+No+module+named+%27_cvxcore%27). In addition, I've seen several of cvxpy's TravisCI builds mention "RuntimeError: module compiled against API version .... ".

However, I haven't seen these issues one-next-to-another before.

[rileyjmurray]

Of 11 builds at the link you provided, only one failed. It's the only what has PRE=1, i.e. the one that tries to use pre-built wheels for dependencies. The only cvxpy distribution available via pip is the source distribution; there are no pre-built wheels. I'm not sure what the behavior of pip is when you install cvxpy in that way, but whatever it is, it seems to not be working.

[skoudoro]

we have no longer this error since this weekend. It is still an enigma for me (even if I supposed that #558 fix it).

I close it since it is fixed.

Thanks CVXpy Team