Re: [libgpiod][PATCH 0/2] support casting line.Value to bool

[Kent Gibson <warthog618@gmail.com>]

On Wed, May 22, 2024 at 09:22:50AM -0700, brgl@bgdev.pl wrote:
> On Wed, 22 May 2024 02:46:41 +0200, Kent Gibson <warthog618@gmail.com> said:
> > While writing a gpiod plugin for gpiozero (Python), I had to map line.Value
> > to its bool equivalent.  Casting seemed the obvious way to go, as it is
> > essentially a boolean, but that didn't work as I expected - it always
> > returned True. This is the case for any Python type that does not provide
> > a suitable conversion operator.
> >
> > This series adds support for casting line.Value to bool.
> >
>
> Ha! Interesting. Do you think we may need it anywhere else too?
>

I guess the same applies to the C++ and Rust bindings - I'll have to
check.

> > Patch 1 adds a test that comfirms the existing behaviour.
> > Patch 2 adds the __bool__() operator to make the Value behave as one
> > might expect.
> >
> > As an aside, I couldn't for the life of me work out how to run the complete
> > python test suite.  There are no hints in the documentation.
> >
> > There is a python-tests-run target in the Makefile, but that didn't work:
> >
> > ~/libgpiod/bindings/python$ make python-tests-run
> > PYTHONPATH=/home/kent/libgpiod/bindings/python
> > LD_LIBRARY_PATH=/home/kent/libgpiod/lib/.libs/:\
> > 	/home/kent/libgpiod/tests/gpiosim/.libs/ \
> > python3 -B -m tests
> > /bin/bash: line 2: /home/kent/libgpiod/tests/gpiosim/.libs/: Is a directory
> > make: *** [Makefile:677: python-tests-run] Error 126
> >
> > I tried fixing that but I still couldn't satisfy ld wrt the gpiosim
> > (I don't have libgpiod installed - just using the local build),
> > so gave up and called this particular test directly with
> >
>
> I typically run it like this:
>
>     PYTHONPATH=./bindings/python
> LD_LIBRARY_PATH=./lib/.libs/:./tests/gpiosim/.libs/:bindings/python/
> python -B -m tests
>

So a one-liner?

That gives me:

$ PYTHONPATH=./bindings/python LD_LIBRARY_PATH=./lib/.libs/:./tests/gpiosim/.libs/:bindings/python/ python3 -B -m tests
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/home/kent/libgpiod/bindings/python/tests/__main__.py", line 7, in <module>
    from .tests_chip import *
  File "/home/kent/libgpiod/bindings/python/tests/tests_chip.py", line 8, in <module>
    from . import gpiosim
  File "/home/kent/libgpiod/bindings/python/tests/gpiosim/__init__.py", line 4, in <module>
    from .chip import Chip
  File "/home/kent/libgpiod/bindings/python/tests/gpiosim/chip.py", line 4, in <module>
    from . import _ext
FileNotFoundError: [Errno 2] No such file or directory

That might also be as far as I got previously - I may've been mis-remembering
that the final hurdle was an import error, not an ld issue, though both are
looking for a module they can't find, so basically the same thing.

Cheers,
Kent.