Troubleshooting

For guidance on debugging an installation, see Frequently asked questions.

Problems with git

First, make sure you have a clean build and install (see How to completely remove Matplotlib), get the latest git update, install it and run a simple test script in debug mode:

rm -rf /path/to/site-packages/matplotlib*
git clean -xfd
git pull
python -m pip install -v . > build.out
python -c "from pylab import *; set_loglevel('debug'); plot(); show()" > run.out

and post build.out and run.out to the matplotlib-devel mailing list (please do not post git problems to the users list).

Of course, you will want to clearly describe your problem, what you are expecting and what you are getting, but often a clean build and install will help. See also Get help.

Unlink of file */_c_internal_utils.cp311-win_amd64.pyd failed

The DLL files may be loaded by multiple running instances of Matplotlib; therefore check that Matplotlib is not running in any other application before trying to unlink this file. Multiple versions of Matplotlib can be linked to the same DLL, for example a development version installed in a development conda environment and a stable version running in a Jupyter notebook. To resolve this error, fully close all running instances of Matplotlib.

Windows compilation errors

If the compiled extensions are not building on Windows due to errors in linking to Windows’ header files, for example ../../src/_tkagg.cpp:133:10: error: 'WM_DPICHANGED' was not declared in this scope, you should check which compiler Meson is using:

Build type: native build
Project name: matplotlib
Project version: 3.9.0.dev0
C compiler for the host machine: cc (gcc 7.2.0 "cc (Rev1, Built by MSYS2 project) 7.2.0")
C linker for the host machine: cc ld.bfd 2.29.1
C++ compiler for the host machine: c++ (gcc 7.2.0 "c++ (Rev1, Built by MSYS2 project) 7.2.0")
C++ linker for the host machine: c++ ld.bfd 2.29.1

Our dependencies documentation lists the minimum header version if you intended to use MSYS2. If you intended to use MSVC then you may need to force Meson to use MSVC.