Python: OSError: cannot load library libcairo.so.2

Question

I'm having some trouble running a python script on my Windows 7 platform. I've installed Python and also cairo, last one using "pip". I'm running the script using this command:

C:\Python34>python.exe label/make_label.py

and I get the following error message:

Traceback (most recent call last):
  File "label/make_label.py", line 6, in <module>
    import cairocffi as cairo
  File "C:\Python34\lib\site-packages\cairocffi\__init__.py", line 41, in <modul
e>
    cairo = dlopen(ffi, *CAIRO_NAMES)
  File "C:\Python34\lib\site-packages\cairocffi\__init__.py", line 34, in dlopen

    return ffi.dlopen(names[0])  # pragma: no cover
  File "C:\Python34\lib\site-packages\cffi\api.py", line 118, in dlopen
    lib, function_cache = _make_ffi_library(self, name, flags)
  File "C:\Python34\lib\site-packages\cffi\api.py", line 411, in _make_ffi_libra
ry
    backendlib = _load_backend_lib(backend, libname, flags)
  File "C:\Python34\lib\site-packages\cffi\api.py", line 400, in _load_backend_l
ib
    return backend.load_library(name, flags)
OSError: cannot load library libcairo.so.2: error 0x7e

What I've already done is the following:

Added the PATH to GTK/bin in the environmental variable
I check the folder GTK/bin and found "libcairo-2.dll" so I renamed it to libcairo.so

I don't know what other information could be useful in solving this but please let me know and I'll try to add it.

You have to make sure Windows (and Python) can find libcairo-2.dll. I doubt Windows/Python is automatically searching in GTK/bin. I'm not sure either that renaming the dll file to an so extension is a good thing to do. — , Jan 29 '15 at 09:49
Well, what I did was to add the location of libcairo.dll (and also libcairo.so) to the PATH of environmental variables. I've been assuming that it tries to check that location. How else can I point Python in the right direction? — Niddro, Jan 29 '15 at 09:51

score 41 · Answer 1 · answered Mar 08 '16 at 23:32

41

On Mac OS X using homebrew:

brew install cairo
brew install pango

answered Mar 08 '16 at 23:32

Hexatonic

2,251
2
21
26

score 9 · Answer 2 · answered Sep 17 '20 at 22:05

9

I just fixed this on Mac OSX 10.13 with an Anaconda Python installation and cairosvg:

$ conda install cairo pango gdk-pixbuf libffi cairosvg
$ cairosvg image.svg -o image.png

I got the idea from https://cairosvg.org/documentation/, which says that all its dependencies can be installed with WeasyPrint. WeasyPrint's documentation for installation on MacOSX at https://weasyprint.readthedocs.io/en/latest/install.html#macos says to get the dependencies from HomeBrew:

brew install python3 cairo pango gdk-pixbuf libffi

So I tried it with conda instead and it worked fine.

answered Sep 17 '20 at 22:05

Harry Howard

91
1
1

Works nicely through conda. (Win10) – YTZ Jan 19 '21 at 19:20
You saved my day bro! This answer is great and works! – Vahid Msm Nov 15 '21 at 19:14
You saved my day bro! This answer is great and works! – Vahid Msm Nov 15 '21 at 19:14
the only answer that fixes the issue on my M1 Pro! – Tristan Bilot Mar 16 '23 at 14:25

score 5 · Accepted Answer · answered Jan 29 '15 at 10:00

5

It seems cairo depends a shared library which is not in standard search library, however, the python is calling dlopen to dynamic load the library, so you could try to put the libcairo.so.2(if it's a link, then make sure the reference locates at the same folder) in the working directory. You can also try pkg-config to set the environment. see here http://people.freedesktop.org/~dbn/pkg-config-guide.html

answered Jan 29 '15 at 10:00

Cui Heng

1,265
8
10

You're indeed correct. By putting the libcairo.so file in the working directory, the script could go further. However, it started to ask for more lib-files so I ended up chucking the whole folder there, didn't have to to figure out exactly which ones were needed. – Niddro Jan 29 '15 at 12:55
If you follow the link, and install the exe mentioned in the link with all the default options it would work. **Note:** Make sure you close and reopen the python terminal or jupyter notebook server. – Hissaan Ali Apr 06 '21 at 10:19

score 5 · Answer 4 · edited Nov 18 '19 at 23:43

I just had the same issue ("OSError: cannot load library libcairo.so.2: error 0x7e"), and this is how I solved the problem on Windows (Windows 7 x64, Python 3.4.2 x86 (MSC v.1600 32 bit)):

downloaded an all-in-one bundle of the GTK+ stack including 3rd-party dependencies (which contains libcairo-2.dll and other Cairo-related libraries)
extracted this archive to a path which does NOT contain spaces _{(e.g. C:\Programs\gtk+)}
added the extracted directory's bin subdirectory (which contains the mentioned libcairo-2.dll and other necessary files) to the PATH
- Win+R, SystemPropertiesAdvanced
- Environment Variables...
- added this directory to the Path variable (either to the user variables or system variables, after a semicolon) _{(e.g. ...;C:\foo;C:\Programs\gtk+)}
- OK
pip install cairosvg
tested it with a very simple code, which already had worked:

import cairosvg
testsvg = '<svg height="30" width="30">\
    <text y="10">123</text>\
    </svg>'
svgConvertedToPng = cairosvg.svg2png(bytestring=testsvg)
print(svgConvertedToPng)

the link to the all in one bundle does not work anymore – Anderas Jun 21 '20 at 06:55 — Anderas, Jun 21 '20 at 06:55

score 4 · Answer 5 · answered Jun 22 '20 at 17:00

4

Solved on Windows 10 as follows:

download the headless UniConverter installer
Find where it installed and add its dll subdirectory to the system path.
Close and re-open the command window to get the updated path.

answered Jun 22 '20 at 17:00

Handcraftsman

6,863
2
40
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score 1 · Answer 6 · answered Mar 21 '23 at 17:16

What I found for MAC OSX when searching the internet for a quick solution.

So after installation of the external library with homebrew:

brew install cairo #and other necessary stuff

library linking

ln -s /opt/homebrew/lib/libcairo.2.dylib .

Need to link lib to run the python code, it is working for me.

Python: OSError: cannot load library libcairo.so.2

6 Answers6