Re: [libgpiod][PATCH V10 2/6] bindings: rust: Add libgpiod crate

[Bartosz Golaszewski <brgl@xxxxxxxx>]

> +/// Get the API version of the libgpiod library as a human-readable string.
> +pub fn libgpiod_version() -> Result<&'static str> {
> +    // SAFETY: The string returned by libgpiod is guaranteed to live forever.
> +    let version = unsafe { gpiod::gpiod_version_string() };
> +
> +    if version.is_null() {
> +        return Err(Error::NullString("GPIO library version"));
> +    }
> +
> +    // SAFETY: The string is guaranteed to be valid here by the C API.
> +    unsafe { CStr::from_ptr(version) }
> +        .to_str()
> +        .map_err(Error::StringNotUtf8)
> +}
> +

This is not a blocker, I will apply this series to master later and we
can add modifications on top of that, but I am now questioning the
need for this function here and also the value of __version__ in
Python bindings.

Previously the python bindings were built with autotools as part of
the whole library. In v2 python now has a proper setup.py script and I
intend to publish the bindings on pypi. It can now be built separately
from the rest of the libgpiod code as long as the system satisfies the
dependency for libgpiod. Example: I will split the yocto recipe for
libgpiod into one for the core lib + tools + C++ bindings and another
for python that will go to meta-python. The latter will depend on the
libgpiod package but will be built in a separate sysroot.

In that case keeping the libgpiod API version as the Python's package
__version__ (which made sense before when that code was closely
integrated with libgpiod core) is no longer necessary. I'm thinking
about setting __version__ to v2.0.0 (because we already had python
bindings with v1.x.y versioning out there) but decoupling it from
libgpiod's API version.

In your rust code all the crates already have their own versions that
don't follow libgpiod's API's version. I think we should drop this
function. What do you think?

Also: is there a standardized way for crates to inspect their version?
As in: println!(crate.version()) or something?

Bart