[bug#27355] [PATCH 3/7] gnu: Add libsigrokdecode.

[Theodoros Foradis <theodoros.for@openmailbox.org>]

Hello,

> the README lists some more dependencies:
>
>  - doxygen (optional, only needed for the C API docs)
>  - graphviz (optional, only needed for the C API docs)
>
> Do you think it makes sense to build the API docs?
>

I recall adding those two as native-inputs but the API docs not
building. I will try again though, and see if I can get it to work. It
makes sense to me to have the docs.

> Also, reading srd.c it seems that this library embeds Python.  Is it still supposed to be a propagated-input then?  It doesn't need the executable at runtime or anything.  Users probably do need the Python standard library, so I guess it's OK...  Hartmut, what do you think?
>

libsigrokdecode.pc, that is the pkg-config file  lists python in
Requires.private. If python is not propagated, libsigrok which depends
on libsigrokdecode cannot be built.

Maybe there is another way for this to work? I saw that done in another
package.

> Extra Python scripts for libsigrokdecode can be installed by the user into ${XDG_DATA_HOME-.local/share}/libsigrokdecode/decoders which is nice.
>
> Additionally, there's an environment variable SIGROKDECODE_DIR too.

Does the package have to set any native-search-paths for this, to let
the users know of the environment variable?

-- 
Theodoros Foradis