Bug report

Bug summary

On some Windows machines (including Windows 10 and Windows 7), we experienced ImportError: DLL load failed: The specific module could not be found after upgrading from Matplotlib 3.3.0 to 3.3.1.

Code for reproduction

import matplotlib would trigger the import error while trying to import ft2font.

Actual outcome

In [1]: import matplotlib
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-1-0484cd13f94d> in <module>
----> 1 import matplotlib

c:\users\nzlab\envs\nta-1465\lib\site-packages\matplotlib\__init__.py in <module>
    172
    173
--> 174 _check_versions()
    175
    176

c:\users\nzlab\envs\nta-1465\lib\site-packages\matplotlib\__init__.py in _check_versions()
    157     # Quickfix to ensure Microsoft Visual C++ redistributable
    158     # DLLs are loaded before importing kiwisolver
--> 159     from . import ft2font
    160
    161     for modname, minver in [

ImportError: DLL load failed: The specified module could not be found.

Expected outcome

No error should be presented.

Matplotlib version

• Operating system: Windows 7 (64bit), Windows 10 (64bit)
• Matplotlib version: 3.3.1
• Matplotlib backend (print(matplotlib.get_backend())): Qt5Agg
• Python version: Python 3.7.6
• Jupyter version (if applicable):
• Other libraries: Microsoft Visual C++ 2015-2019 Redistributable (x64) - 14.27.29016 NOT INSTALLED

**Further diagnose shows: **

• ft2font.cp37-win_amd64.pyd (Matplotlib 3.3.0) links VCRUNTIME140.dll
• ft2font.cp37-win_amd64.pyd (Matplotlib 3.3.1) links VCRUNTIME140_1.dll

Those computers which have DLL load failed don't have VCRUNTIME140_1.dll in DLL search path.

Solution
Installing the latest Visual Studio 2015, 2019 and 2019 redistributable should address the issue.

Question
Is changing in VC++ API (from 14 to 14.1) an intentional move on Matplotlib 3.3.1 for Windows release? If so, should the VC++ dependency to be added to Installation Guide?