gobject-2.0-0 not able to load on macbook - python-3.x

Question

I am facing this error when I start my flask application on Python3 and Mac OS:
OSError: cannot load library 'gobject-2.0-0': dlopen(gobject-2.0-0, 2): image not found. Additionally, ctypes.util.find_library() did not manage to locate a library called 'gobject-2.0-0'
I am using weasyprint in my project which is causing this issue.
I tried to install glib and it is installed in my system.

Answer 1

I just managed the same issue on my Mac M1.
The problem was that symlinks to the libraries were not created (can't say should it be done by homebrew or weasyprint when installation).
So, I had to do it manually
sudo ln -s /opt/homebrew/opt/glib/lib/libgobject-2.0.0.dylib /usr/local/lib/gobject-2.0
sudo ln -s /opt/homebrew/opt/pango/lib/libpango-1.0.dylib /usr/local/lib/pango-1.0
sudo ln -s /opt/homebrew/opt/harfbuzz/lib/libharfbuzz.dylib /usr/local/lib/harfbuzz
sudo ln -s /opt/homebrew/opt/fontconfig/lib/libfontconfig.1.dylib /usr/local/lib/fontconfig-1
sudo ln -s /opt/homebrew/opt/pango/lib/libpangoft2-1.0.dylib /usr/local/lib/pangoft2-1.0
This solved the problem.
In order to TEST if Python can find the library you may run
from ctypes.util import find_library
find_library('gobject-2.0') # Pass any other lib name as an argument
UPD. There is no such problem if you install python with homebrew.

Answer 2

If you installed weasyprint package in your virtual env but did not installed some required packages for that, then that might be the reason. It was actually, in my case.
If you're mac user you need install pango and libffi, not to mention python as well.
Installation guide on mac
brew install python pango libffi
(venv) pip install weasyprint

Answer 3

To expand on the existing answers on Apple Silicon (M1) Macs:
If you have installed the packages with Homebrew and they are still not found or linked under /usr/local/lib, it is because they are installed on arm64 and found in /opt/homebrew/lib instead.
If you're using Python installed with Homebrew it should work without any extra work, however system Python and any managed Python versions (e.g. installed with Pyenv) will require some configuration.
1. Manual symlinking
Instead of linking each library individually to /usr/local/lib, you can link the /opt/homebrew/lib contents (as long as you don't have an existing /usr/local/lib directory):
sudo ln -s /opt/homebrew/lib /usr/local/lib
This will work as long as the library you're looking for is not from a keg-only formula (those will have to be linked individually).
2. Environment variables
A lot of answers point to setting some environment variable, like LDFLAGS or DYLD_LIBRARY_PATH to add search paths for libraries, but these will not work with Python based on my testing:
macOS comes with System Integrity Protection (SIP) which, among other things, sanitizes your environment variables in subprocesses, for example Python. Anything starting with LD or DYLD will be purged, so setting the environment variables in your terminal profile will not work.
You can Disable SIP to get these working, but Apple recommends only doing it temporarily when needed.
If you decide to go this route, here are a few options:
In Homebrew's Github discussions the question was answered by setting LDFLAGS:
export LDFLAGS=-L/opt/homebrew/lib
Similarly you could add the necessary paths to DYLD_LIBRARY_PATH
export DYLD_LIBRARY_PATH=/opt/homebrew/lib

Answer 4

I had the same issue after the homebrew update. Turned out the issue was because of the older pango lib version.
I did brew install pango
This upgraded pango lib from 1.48.2 -> 1.50.4 which internally installed gobject's latest version as dep. And my issue got resolved.