py310-dlib: Problem loading library

[cbitterfield (Colin Bitterfield)]

Python 3.10.10 (main, Feb 24 2023, 04:10:25) [Clang 14.0.0 (clang-1400.0.29.202)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import dlib
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/dlib/__init__.py", line 19, in <module>
    from _dlib_pybind11 import *
ImportError: dlopen(/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/_dlib_pybind11.cpython-310-darwin.so, 0x0002): symbol not found in flat namespace '_png_do_expand_palette_rgb8_neon'

[ryandesign (Ryan Carsten Schmidt)]

Possibly ​https://github.com/davisking/dlib/commit/90a8be6400fce56f739f6c5a44bd795233d426f1 will fix it?

[ryandesign (Ryan Carsten Schmidt)]

That commit is in the code path for when libpng is not found. And the dlib port and its subports do not declare a dependency on libpng so it won't be there, at least not on buildbot builds. So the solution may be to add the libpng dependency and revbump. Other opportunistically-used dependencies may need to be added too.

[ryandesign (Ryan Carsten Schmidt)]

You can check whether this might help your problem by installing libpng (this might not do anything since it is likely it is already installed):

sudo port install libpng

And then rebuilding py310-dlib from source:

sudo port -ns upgrade --force py310-dlib