Matplotlib 2.0.0b3 wheel can't load libpng in OS X 10.6

[aivarannamaa]

I installed matplotlib to Python 3.5 on OS X 10.6 with "pip install --pre matplotlib", ran following code

import matplotlib.pyplot as plt
plt.plot([1,2,3,4])
plt.ylabel('some numbers')
plt.show()

and got

Traceback (most recent call last):
  File "/Users/aivar/Downloads/makinggames/plo.py", line 1, in <module>
    import matplotlib.pyplot as plt
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/pyplot.py", line 29, in <module>
    import matplotlib.colorbar
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/colorbar.py", line 36, in <module>
    import matplotlib.contour as contour
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/contour.py", line 23, in <module>
    import matplotlib.text as text
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/text.py", line 33, in <module>
    from matplotlib.backend_bases import RendererBase
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/backend_bases.py", line 63, in <module>
    import matplotlib.textpath as textpath
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/textpath.py", line 20, in <module>
    from matplotlib.mathtext import MathTextParser
  File "/Users/aivar/.thonny/lib/python/site-packages/matplotlib/mathtext.py", line 62, in <module>
    import matplotlib._png as _png
ImportError: dlopen(/Users/aivar/.thonny/lib/python/site-packages/matplotlib/_png.cpython-35m-darwin.so, 2): Symbol not found: _inflateReset2
  Referenced from: /Users/aivar/.thonny/lib/python/site-packages/matplotlib/.dylibs/libpng16.16.dylib
  Expected in: /usr/lib/libz.1.dylib
 in /Users/aivar/.thonny/lib/python/site-packages/matplotlib/.dylibs/libpng16.16.dylib

[jenshnielsen]

@matthew-brett Do you have any insight into this? It looks like zlib on 10.6 is too old to have the relevant symbols defined

[matthew-brett]

Can reproduce, will try building a new zlib in the wheel build recipe.

[matthew-brett]

OSX 10.6 has zlib 1.2.3:

$ otool -L /usr/lib/libz.dylib 
/usr/lib/libz.dylib:
    /usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.3)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 125.2.0)

inflateReset2 added in zlib 1.2.4 - from : http://zlib.net/

Version 1.2.4 has many changes over 1.2.3, including these improvements:
    [snip]
    Added inflateReset2() and inflateMark() functions, the latter to aid in random access applications 

travis-ci has OSX 10.9, which has zlib 1.2.5, so libpng compiles expecting 1.2.5 and then barfs when it tries to load the symbol from 1.2.3.

I tried building matplotlib on OSX with an up-to-date copy of zlib. @aivarannamaa - does this work for you?

curl -LO https://3f23b170c54c2533c070-1c8a9b3114517dc5fe17b7c3f8c63a43.ssl.cf2.rackcdn.com/matplotlib-2.0.0b3-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl
pip install matplotlib-2.0.0b3-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl

etc. If so I'll upload these to pypi for more testing.

[aivarannamaa]

This wheel seems to be for Python 2.7. Could you also create one for Python 3.5?

I tried to install it to 2.7 but building a dependency (subprocess32) failed because I don't have build tools on my virtual OS X 10.6 (And I don't want to install them in order to keep the machine fresh for testing my app.)

[matthew-brett]

Oh - dear - sorry about subprocess2 - I'll investigate.

But - there are already Python 3.5 wheels at the same location - could you try that?

[aivarannamaa]

Great success!
Python 3.5 wheel works!

[matthew-brett]

Great - thanks for testing.

I've uploaded the new wheels to pypi. Can you try again, to check it is working from pypi?

pip install --pre matplotlib

[tacaswell]

Closing this as it looks like @matthew-brett resolved it by uploading new wheels to pypi.

[aivarannamaa]

Funny, after installing from pypi I still get the same error.

I started with pip3 uninstall matplotlib.

Then I did pip3 install --pre matplotlib but it wasn't good because it took the wheel from pip's cache.
I uninstalled again and did pip3 install --pre --no-cache-dir matplotlib. This time I saw it was downloading the wheel:

Collecting matplotlib
  Downloading matplotlib-2.0.0b3-cp35-cp35m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (12.7MB)
    100% |████████████████████████████████| 12.7MB 1.9MB/s 
Requirement already satisfied (use --upgrade to upgrade): cycler>=0.10 in ./.thonny/lib/python/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): pytz in ./.thonny/lib/python/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): python-dateutil in ./.thonny/lib/python/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): numpy>=1.6 in ./.thonny/lib/python/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): six>=1.10 in ./Desktop/Thonny.app/Contents/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): pyparsing!=2.0.0,!=2.0.4,!=2.1.2,>=1.5.6 in ./.thonny/lib/python/site-packages (from matplotlib)
Installing collected packages: matplotlib
Successfully installed matplotlib-2.0.0b3

After this I still got loading error mentioned above.

I tried also pip3 install --pre --no-cache-dir --upgrade matplotlib but the result was the same.

[matthew-brett]

Thanks very much for testing.

So, what I did was upload new builds of matplotlib with a new "build tag" in their name. The new wheels have names like this:

matplotlib-2.0.0b3-1-cp35-cp35m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl

where -1- is the build tag. It looks like pip is still trying to get the older versions without the build tag. I've deleted these from pypi just now, and with this:

pip install --no-cache-dir --pre matplotlib

I now get the right wheel. I think the cached pypi listing times out after a while, so this should be the default in due course (without --no-cache-dir). Does this work for you now?

[aivarannamaa]

Now it works!

[matthew-brett]

Excellent - thanks for your persistence.

[aivarannamaa]

Thanks for your persistence :)