No module named 'libqtile._ffi_pango' when installing from source

The issue:

Per https://github.com/qtile/qtile/discussions/3101 , I am trying to document all the (far too many) library problems I encounter when trying to run Qtile, because I think they get in the way of getting proper packaging.

I am trying to install Qtile following the Installing from sources section.

I am running Ubuntu 19.10 Eoan, but since I’m having library problems also with newer Ubuntu versions, I might as well start from here.

Following the docs, I install: sudo apt install python3-cffi sudo apt install xserver-xorg sudo apt install python3-xcffib sudo apt install python3-cairocffi sudo apt install libpangocairo-1.0-0 sudo pip install --no-cache-dir cairocffi

pip complains that Requirement already satisfied: cairocffi in /usr/lib/python3/dist-packages (0.9.0) so I uninstall the deb:

sudo apt remove python3-cairocffi

And try again with pip: sudo pip install --no-cache-dir cairocffi

At this point, I try to run qtile and I get:

nw@red ~$ qtile --version
Traceback (most recent call last):
  File "/home/nw/qtile/libqtile/pangocffi.py", line 51, in <module>
    from libqtile._ffi_pango import ffi
ModuleNotFoundError: No module named 'libqtile._ffi_pango'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/qtile", line 5, in <module>
    from libqtile.scripts.main import main
  File "/home/nw/qtile/libqtile/scripts/main.py", line 6, in <module>
    from libqtile.scripts import check, cmd_obj, migrate, run_cmd, shell, start, top
  File "/home/nw/qtile/libqtile/scripts/check.py", line 29, in <module>
    from libqtile import confreader
  File "/home/nw/qtile/libqtile/confreader.py", line 31, in <module>
    from libqtile.backend.x11 import core
  File "/home/nw/qtile/libqtile/backend/x11/core.py", line 36, in <module>
    from libqtile import config, hook, utils
  File "/home/nw/qtile/libqtile/config.py", line 36, in <module>
    from libqtile.backend import base
  File "/home/nw/qtile/libqtile/backend/base.py", line 11, in <module>
    from libqtile import drawer, pangocffi, utils
  File "/home/nw/qtile/libqtile/drawer.py", line 35, in <module>
    from libqtile import pangocffi, utils
  File "/home/nw/qtile/libqtile/pangocffi.py", line 53, in <module>
    raise ImportError("No module named libqtile._ffi_pango, be sure to run `./scripts/ffibuild`")
ImportError: No module named libqtile._ffi_pango, be sure to run `./scripts/ffibuild`

Ok, let’s run the script:

w@red ~/qtile master$ ./scripts/ffibuild 
building pango
building xcursors
building pulseaudio volume control
libqtile/widget/_pulse_audio.c:541:14: fatal error: pulse/sample.h: No such file or directory
  541 |     #include "pulse/sample.h"
      |              ^~~~~~~~~~~~~~~~
compilation terminated.
Traceback (most recent call last):
  File "/usr/lib/python3.8/distutils/unixccompiler.py", line 117, in _compile
    self.spawn(compiler_so + cc_args + [src, '-o', obj] +
  File "/usr/lib/python3.8/distutils/ccompiler.py", line 910, in spawn
    spawn(cmd, dry_run=self.dry_run)
  File "/usr/lib/python3.8/distutils/spawn.py", line 36, in spawn
    _spawn_posix(cmd, search_path, dry_run=dry_run)
  File "/usr/lib/python3.8/distutils/spawn.py", line 157, in _spawn_posix
    raise DistutilsExecError(
distutils.errors.DistutilsExecError: command 'x86_64-linux-gnu-gcc' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/cffi/ffiplatform.py", line 51, in _build
    dist.run_command('build_ext')
  File "/usr/lib/python3.8/distutils/dist.py", line 985, in run_command
    cmd_obj.run()
  File "/usr/lib/python3.8/distutils/command/build_ext.py", line 340, in run
    self.build_extensions()
  File "/usr/lib/python3.8/distutils/command/build_ext.py", line 449, in build_extensions
    self._build_extensions_serial()
  File "/usr/lib/python3.8/distutils/command/build_ext.py", line 474, in _build_extensions_serial
    self.build_extension(ext)
  File "/usr/lib/python3.8/distutils/command/build_ext.py", line 528, in build_extension
    objects = self.compiler.compile(sources,
  File "/usr/lib/python3.8/distutils/ccompiler.py", line 574, in compile
    self._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)
  File "/usr/lib/python3.8/distutils/unixccompiler.py", line 120, in _compile
    raise CompileError(msg)
distutils.errors.CompileError: command 'x86_64-linux-gnu-gcc' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "./libqtile/widget/pulseaudio_ffi.py", line 421, in <module>
    pulseaudio_ffi.compile()
  File "/usr/lib/python3/dist-packages/cffi/api.py", line 725, in compile
    return recompile(self, module_name, source, tmpdir=tmpdir,
  File "/usr/lib/python3/dist-packages/cffi/recompiler.py", line 1535, in recompile
    outputfilename = ffiplatform.compile('.', ext,
  File "/usr/lib/python3/dist-packages/cffi/ffiplatform.py", line 22, in compile
    outputfilename = _build(tmpdir, ext, compiler_verbose, debug)
  File "/usr/lib/python3/dist-packages/cffi/ffiplatform.py", line 58, in _build
    raise VerificationError('%s: %s' % (e.__class__.__name__, e))
cffi.VerificationError: CompileError: command 'x86_64-linux-gnu-gcc' failed with exit status 1
building Wayland libinput interface
Traceback (most recent call last):
  File "./libqtile/backend/wayland/libinput_ffi_build.py", line 1, in <module>
    import wlroots.ffi_build as wlr
ModuleNotFoundError: No module named 'wlroots'

Surprisingly, after this slew of errors, Qtile actually runs.

However, the docs and/or the error reporting could be improved?

I have seen so many library problems that at first I didn’t even notice that I was being asked to run a script, and the script gave all the signs of having failed spectacularly.

Maybe also mention to run pip install dbus-next, since there is no deb package for that any more?

[elParaguayo]

Firstly, thanks for looking at this.

Surprisingly, after this slew of errors, Qtile actually runs.

However, the docs and/or the error reporting could be improved?

Yeah, that amount of error messages is pretty ugly. We should try to be a bit neater there (probably one for @m-col as he was looking at minimising wayland requirements at build time)

I have seen so many library problems that at first I didn’t even notice that I was being asked to run a script, and the script gave all the signs of having failed spectacularly.

The script is an important part of the build so needs to be shown in the instructions.

Maybe also mention to run pip install dbus-next, since there is no deb package for that any more?

Don’t know about this one. It’s an optional requirement. You don’t need it to run qtile.

Appreciate the frustrations you’re encountering but please do keep pasting them here because if there are parts of the code that need fixing (e.g. better error handling) then we can pick those up.

[SweepingBishops]

Thanks! I’ve just started reading through the docs again to identify room for improvement. And the getting started section is definitely one of them. Post any further suggestions to #1679.