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matplotlib crashes on OS X when saving to JPEG and then displaying the plot #4194
Description
Here is the minimal code to produce the crash on OS X Yosemite, with Python 2.7.9 compiled by homebrew.
# -*- coding: utf-8 -*-
import numpy
import matplotlib.pyplot as plt
plt.plot(numpy.linspace(0, 1, 1000), numpy.random.randn(1000))
plt.savefig('test.jpg')
plt.show()The error message is
Assertion failed: (s->stack->next != NULL), function CGGStackRestore, file Context/CGGStack.c, line 77.
The crash does not happen if the savefig and show call are swapped, or when saving to png/pdf/svg file. It only happens when pyplot is called in this sequence, and when the format is jpg.
Activity
tacaswell commentedon Mar 5, 2015
What backend are you using? I suspect the OSX backend from the error. Is that the full error message you get?
I can not reproduce this on py3 + linux + qtagg
attn @mdehoon
netheril96 commentedon Mar 5, 2015
@tacaswell
Yes, it is the MacOSX backend, and the error message is all that I get.
If I manually specify the
aggbackend, it works normally as well. So this is a bug specific to OSX backend.jenshnielsen commentedon Mar 5, 2015
Which Matplotlib version do you use? I could not reproduce this on master (1.5.dev1)
netheril96 commentedon Mar 5, 2015
@jenshnielsen
matplotlib (1.4.3)
Python 2.7.9
Mac OS X backend
mdehoon commentedon Mar 6, 2015
I could not reproduce this with Python 2.7.9 and matplotlib 1.4.3 on Mac OS X 10.9 or 10.10.
Can you try changing backend_macosx.py to return immediately from _print_bitmap ?
So
Then, with some luck, we can find out exactly where the problem is occurring.
netheril96 commentedon Mar 6, 2015
@mdehoon
The error message goes away, and obviously the
jpgis never created.I took the liberty of poking around in that function, and the error occurs in the call
self.write_bitmap(filename, width, height, dpi)Even weirder is that running this script in
ipdbline by line does not produce any error, and does produce a correctjpegfile.mdehoon commentedon Mar 6, 2015
I am guessing that these two lines:
in the function FigureCanvas_write_bitmap in _macosx.m are causing the problem. Can you try moving these two lines down to just before
, recompile, and see if the problem still occurs?
netheril96 commentedon Mar 6, 2015
@mdehoon
The problem still occurs after the change and recompile/reinstallation.
Deleting that two release calls doesn't help, either.
netheril96 commentedon Mar 6, 2015
@mdehoon
I also tried recompiling python as well as installing matplotlib from this git repository. The assertion failure is still there.
mdehoon commentedon Mar 6, 2015
Sorry, there is not much I can do as I cannot reproduce this error. I would suggest to remove more of the code in FigureCanvas_write_bitmap and see if the problem disappears at some point.
mdboom commentedon Mar 21, 2016
Possibly fixed by #6178, but since we're having trouble reproducing, it's hard to say.