OSError: cannot load library 'gobject-2.0': error 0x7e.

[d-vyd]

I followed the instructions for installing on Windows with Python 64 bit. I'm using an Anaconda installation but "conda install weasyprint" did not find a package, so I used "pip". I'm getting the error below when trying to test weasyprint. After seeing the error, I tried to manually install "glib" using "conda". It installed. But, did not fix the issue.

C:\Users\david>python -m weasyprint http://weasyprint.org weasyprint.pdf
Traceback (most recent call last):
File "C:\Users\david\Anaconda3\lib\runpy.py", line 183, in _run_module_as_main
mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
File "C:\Users\david\Anaconda3\lib\runpy.py", line 142, in _get_module_details
return get_module_details(pkg_main_name, error)
File "C:\Users\david\Anaconda3\lib\runpy.py", line 109, in get_module_details
import(pkg_name)
File "C:\Users\david\Anaconda3\lib\site-packages\weasyprint_init.py", line 440, in
from .css import preprocess_stylesheet # noqa isort:skip
File "C:\Users\david\Anaconda3\lib\site-packages\weasyprint\css_init.py", line 30, in
from . import computed_values, media_queries
File "C:\Users\david\Anaconda3\lib\site-packages\weasyprint\css\computed_values.py", line 17, in
from .. import text
File "C:\Users\david\Anaconda3\lib\site-packages\weasyprint\text.py", line 257, in
'libgobject-2.0.dylib')
File "C:\Users\david\Anaconda3\lib\site-packages\weasyprint\text.py", line 253, in dlopen
return ffi.dlopen(names[0]) # pragma: no cover
File "C:\Users\david\Anaconda3\lib\site-packages\cffi\api.py", line 146, in dlopen
lib, function_cache = _make_ffi_library(self, name, flags)
File "C:\Users\david\Anaconda3\lib\site-packages\cffi\api.py", line 828, in _make_ffi_library
backendlib = _load_backend_lib(backend, libname, flags)
File "C:\Users\david\Anaconda3\lib\site-packages\cffi\api.py", line 823, in _load_backend_lib
raise OSError(msg)
OSError: cannot load library 'gobject-2.0': error 0x7e. Additionally, ctypes.util.find_library() did not manage to locate a library called 'gobject-2.0'

[Tontyna]

Did you install the/a GTK3-Runtime?

[d-vyd]

Yes, I installed GTK3. Is gobject related to GTK? On Oct 17, 2019 2:51 AM, Tontyna <notifications@github.com> wrote: Did you install the/a GTK3-Runtime? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#971?email_source=notifications&email_token=AGJMWFY4P3E2UNPJNQY5U7TQO6SIJA5CNFSM4JBRWDE2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOEBOJBAI#issuecomment-542937217>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AGJMWF6Q2H44IBER7WAVOWLQO6SIJANCNFSM4JBRWDEQ>.

[Tontyna]

Is gobject related to GTK?

Yes. So. As always when it comes to "OSError cannot load library" on Windows it's a matter of PATH resp. the os.path that Python presents to WeasyPrint.

The fact that weasyprint.text complains about gobject-2 instead of cairocffi complaining about cairo-2 tells me that there is another (reduced) GTK-collection in your os.path.
I assume that Anaconda tweaked the environment and inserted its own library path in front of your GTK3 Runtime folder.

Please run the following command in the shell where you start WeasyPrint and check the output.

python -c "import os; print(*os.environ['PATH'].split(os.pathsep), sep='\n')"

[tyoung88]

I am not the original poster, but I am having the exact same issue (I also have anaconda installed).
I ran the command that you asked and see that GTK3-Runtime Win65\bin is the first entry.
As an aside I just installed GTK3... restarted my machine to ensure everything was picked up correctly.

Something else I can check?

[tyoung88]

I checked the folder that the path was pointing to.... I think I found the issue, however I don't understand why it happened.
In the folder where the gtk3 installer ran, the dll file names seem not to be what weasyprint is looking for.
For example in C:\Program Files\GTK3-Runtime Win64\bin I see libgobject-2.0-0.dll instead of libgobject-2.0.dll.
If I manually change the file name so that it matches what weasyprint is looking for, it will load. However it will take me a while to rename all the files.... and I feel there may be an issue I am missing.

let me know if you have any thoughts. Thanks!

[Tontyna]

My (main) dll's are named libgobject-2.0-0.dll, libpango-1.0-0.dll, libpangocairo-1.0-0.dll, too . And WeasyPrint has no problem to load them. So that's not the point.
Having no experience with Anaconda but reading a bit in their docs I fear that Anaconda tries hard to provide its users with a solid environment (including DLLs) and doesn't like people loading things unknown to Anaconda.

Isn't there a way to tell Anaconda's environment what paths it should include?
Isn't there a way to install a recent and complete GTK3 (Cairo, GObject, Pango, PangoCairo) with "conda" or whatever?

[Tontyna]

Had a closer look at Anaconda. Anaconda is just Python with some comfort.
Thus, as I stated above: To make it use your GTK, your GTK must be at the beginning of the os.environ['PATH'] or at least before all other incompatible, incomplete, unwanted, alternate folders.

@tyoung88 -- did you run the python command that prints the paths from the same command prompt or shell where your WeasyPrint fails with OSError?

I'm quite sure you didn't. I'm quite sure you run WeasyPrint from an Anaconda Prompt or similar that activates Anaconda's environment -- and pushes the Anaconda search paths (including a folder called <Anaconda-root>\Library\mingw-w64\bin) a in front of everything.

There mus be an activation script, probably a .bat or .cmd. You could modify that script to keep your GTK3 folder at the top or you could apply a more Pythonic way and use the famous sitecustomize.py solution:

"""
    sitecustomize.py 
    ================

    To ensure the correct GTK3 Runtime
    
    - To activate the GTK for Anaconda and all its environments:
      put the file into **sys.base_prefix**,
      i.e. the path where Anaconda's master python.exe is located.
      i.e. your Anaconda install directory

    - To activate the GTK only in a dedicated environment:
      put the file into the **./Lib/site-packages** folder of that
      environemt
"""
import os

# insert the GTK3 Runtime folder at the beginning
GTK_FOLDER = r'C:\Program Files\GTK3-Runtime Win64\bin'
os.environ['PATH'] = GTK_FOLDER + os.pathsep + os.environ.get('PATH', '')

No need to rename anything 😁

Be aware that some IDE's try to be helpful and insert folders they consider useful into the os.environ['PATH'], too.

[tyoung88]

I just wanted to update after such a complete answer @Tontyna .

I am still unsure why the dlls could not be found properly...
I ran the command you asked for in the same command prompt, which gave the results I shared in my previous post. The good news is that after I renamed the dlls and fixed the way I was using the libraries I got things working. Thank you for the tips and I apologize for not having a better answer on the dlls.

[Tontyna]

I am still unsure why the dlls could not be found properly...

I have a hypothesis, implying Anaconda's mingw-w64 folder. Especially the fact that renaming your DLLs fixes your WeasyPrint problem is a strong indicator. To verify my assumption I'd have to install Anaconda and I'm not keen to do that...

[chickendude]

I had a similar issue and it turned out the GTK2 dlls were getting in the way of the GTK3 ones.

[jannefleischer]

I ran into the same issue in conda and was only able to resolve it, by installing the gtk-libraries from msys2 .

While using the gtk+ 64bit windows installer I got popups on import of weasyprint that said:

"Der Prozedureinsprungspunkt '__cxa_throw_bad_array_new_length' wurde in der DLL 'C:\Program Files\GTK33-Runtime Win64\bin\libgraphite2.dll' nicht gefunden."

(don't know how to translate THAT - who is localizing techy error messages?)

And some other similiar errors.

The initial error said

"OSError: cannot load library 'gobject-2.0': error 0x7e. Additionally, ctypes.util.find_library() did not manage to locate a library called 'gobject-2.0'"

but that isn't actual the error occuring on windows. If I run
from cffi import FFI; ffi=FFI(); ffi.dlopen('libgobject-2.0-0') I get the correct error:

OSError: cannot load library 'C:\Program Files\GTK3-Runtime Win64\bin\libgobject-2.0-0.dll': error 0x7f

And that points to a similiar (and old) issue with cffi:
api.py throws OSError 0x7e when loading libcairo-2.dll

So I am guessing something in conda isn't compatible with the way how the gtk-libraries in the 64bit windows installer are compiled. But on the other hand I may be entirely wrong. I have no clue about compiling anything anywhere.

Long story short: Using msys2 on conda resolved the issue for me.

[Tontyna]

So I am guessing something in conda isn't compatible with the way how the gtk-libraries in the 64bit windows installer are compiled

Sounds reasonable.
But: The DLLs in Tom Schoonjans' GTK3 Runtime are copies/extracts from his own up-to-date msys installation, he doesn't compile them...

[kpierce8]

the sitecustomize.py route worked for me. Just added it to my script before importing weasyprint

[docbrown]

I'm having the same problem with GTK+3 DLLs installed with MSYS2 and copied to an embedded Python 3.8 distribution.

Process Monitor shows that Python looks for libgobject-2.0-0.dll only on the PATH and never in the current directory (where the file actually is), then falls back to looking for gobject-2.0.dll in the PATH and the current directory. I know that Python 3.8 changed DLL resolution for extensions, so I even tried:

.\python.exe -c "import os; os.add_dll_directory(os.getcwd()); import weasyprint"

But that had no effect.

[kwfan]

I got to this page and fixed the problem on my side by a few trials:

The problem root cause on my end is due to multiple libgobject-2.0-0.dll on my system. On your anaconda command prompt, run "where libgobject-2.0-0.dll".

My first output is:
(base) C:\WINDOWS\system32>where libgobject-2.0-0.dll

C:\Program Files (x86)\GtkSharp\2.12\bin\libgobject-2.0-0.dll
C:\Program Files\GTK3-Runtime Win64\bin\libgobject-2.0-0.dll

Since C:\Program Files (x86)\GtkSharp\2.12\bin\ has a higher priority in path variable list, so the wrong dll was found and loaded incorrectly. To fix this, go to edit variable page and edit "path" of system variable, then make C:\Program Files\GTK3-Runtime Win64\bin\ to have a higher position.

Reopen a new command prompt. If your "where" output shows:
(base) C:\WINDOWS\system32>where libgobject-2.0-0.dll

C:\Program Files\GTK3-Runtime Win64\bin\libgobject-2.0-0.dll
C:\Program Files (x86)\GtkSharp\2.12\bin\libgobject-2.0-0.dll

Then you are all set. Hope this can help.