[SOLVED] Cairo/Python issues with WeasyPrint

MisterBark · 07-09-2016, 02:47 PM

Hi,

I successfully installed WeasyPrint.
Cairo is installed too.
I get this error when executing WeasyPrint:

Code:

Traceback (most recent call last):
  File "./WeasyPrint/weasyprint.py", line 2, in <module>
    from weasyprint.__main__ import main
  File "/home/root/WeasyPrint/weasyprint/__init__.py", line 336, in <module>
    from .css import PARSER, preprocess_stylesheet  # noqa
  File "/home/root/WeasyPrint/weasyprint/css/__init__.py", line 30, in <module>
    from . import computed_values
  File "/home/root/WeasyPrint/weasyprint/css/computed_values.py", line 18, in <module>
    from .. import text
  File "/home/root/WeasyPrint/weasyprint/text.py", line 18, in <module>
    import cairocffi as cairo
  File "/root/.local/lib64/python3.4/site-packages/cairocffi/__init__.py", line 46, in <module>
    cairo = dlopen(ffi, 'cairo', 'cairo-2')
  File "/root/.local/lib64/python3.4/site-packages/cairocffi/__init__.py", line 43, in dlopen
    raise OSError("dlopen() failed to load a library: %s" % ' / '.join(names))
OSError: dlopen() failed to load a library: cairo / cairo-2

It seems to be a common problem that no one really understands, I found plenty of topics on the net, but mostly for MacOS.

I tried to reinstall cairo libs, and the cairo and cairocffi of python, same thing.

My machine:
Slackware64, very customized, kernel grsec, no X.

I have another Slackware64 on a desktop, less minimal, and it works.
I can't figure out what makes the difference.

Any suggestions on what to try?
NOTE: I cannot reboot that server, but I mounted /usr in ramfs so I can experiment a bit without messing up the real /usr directory.

Thanks!

MisterBark · 07-09-2016, 06:05 PM

Ok so for anyone passing by here and still struggling with that, I found the problem.
In my case it was because cairo libs were there, but they need X and my system (a server) had no X. Unfortunately once in Python it didn't explain what was wrong with cairo.

So, to check if python finds cairo:

Code:

/usr/bin/python2.7 -c "import ctypes.util; print ctypes.util.find_library('cairo')"

That should return you the file name of the lib being used. If not, it means that python cannot find cairo, so make sure it does.
Now, if it does, you wanna look at what this lib depends on:

In my case:

Code:

# ldd libcairo.so.2.11200.16
        linux-gate.so.1 (0xe1cf9000)
        libpthread.so.0 => /lib/libpthread.so.0 (0xe1ba4000)
        libpixman-1.so.0 => not found
        libfontconfig.so.1 => not found
        libfreetype.so.6 => /usr/lib/libfreetype.so.6 (0xe1af0000)
        libEGL.so.1 => not found
        libdl.so.2 => /lib/libdl.so.2 (0xe1aeb000)
        libpng14.so.14 => /usr/lib/libpng14.so.14 (0xe1abf000)
        libxcb-shm.so.0 => not found
        libxcb-render.so.0 => not found
        libxcb.so.1 => not found
        libXrender.so.1 => not found
        libX11.so.6 => not found
        libXext.so.6 => not found
        libz.so.1 => /usr/lib/libz.so.1 (0xe1aa8000)
        libGL.so.1 => not found
        librt.so.1 => /lib/librt.so.1 (0xe1a9f000)
        libm.so.6 => /lib/libm.so.6 (0xe1a5c000)
        libc.so.6 => /lib/libc.so.6 (0xe18d0000)
        /lib/ld-linux.so.2 (0xe1cfa000)
        libbz2.so.1 => /lib/libbz2.so.1 (0xe18bf000)

As you can see some X libs are missing.
So either you install X, which is really too heavy for a clean server IMO, or you find just the libs it needs.
I copied these files from another Slackware64 same version, and it worked! (I basically copied libX* and a few more to make sure they are all here)
If it doesn't, run ldd on each of these libs listed to see if they miss even more.

Then I had some pango issues with fonts but copying some pango module files and creating ~/.fonts/ with the ttf inside solved the problem.

Best luck!