Since swig-4.4.0 was uploaded to pypi.org a few hours ago, PyMuPDF tests have started failing on MacOS x86_64 and arm64.

• Tests are still passing on Linux and Windows.
• Tests pass fine on MacOS x86_64 and arm64 if we force the use of swig-4.3.1.

PyMuPDF and MuPDF are quite complicated and i haven't yet created a small reproducer, but i though it was worth creating this issue now because this could be quite a serious regression in swig. (Unless of course it's exposing something wrong in our code.)

For example output see Github workflow results at: https://github.com/pymupdf/PyMuPDF/actions/runs/18866039539/job/53833771115. PyMuPDF/MuPDF

The failures seem to be caused by exceptions in Director callbacks.

First there is:

Director error: <class 'TypeError'>: SWIG director type mismatch in output value of type '::fz_font *'

[fz_font is a C struct in MuPDF, wrapped by SWIG. I don't know what function (that returns a fz_font*) is being called here.]

We have code that prints information about exceptions in Director callbacks, and this seems to be failing with:

Director error: <class 'AttributeError'>: 'EncodedFile' object has no attribute 'write'

I don't know what EncodedFile is - there's no such struct/class in MuPDF or PyMuPDF.

Thanks.