Bug#989958: libopencv-*-dev: Missing pkg-config file (.pc)

[Alejandro Colomar (man-pages)]

Hi Jochen,

On 6/21/21 2:33 PM, Jochen Sprickerhof wrote:
> Control: severity -1 wishlist
> 
> Hi Alejandro,
> 
> * Alejandro Colomar <alx.manpages at gmail.com> [2021-06-16 17:31]:
>> None of them contain the needed pkg-conig files for their use, making
>> necessary to install 'libopencv', and making useless the separation into
>> smaller packages.
> 
> You don't need to use pkg-config to build against an OpenCV module, just 
> running gcc with the flags you need will work. Adjusting severity 
> accordingly.
> 

I had some thoughts about this after sending the email.
The problem in the first place is that opencv doesn't provide separate 
pkg-config files for every module.

Maybe Debian could write separate pkg-config files, and maybe offer them 
to upstream OpenCV (I offer myself to help write them if you decide it's 
a good idea).

Yes, for linking against the shared libraries, that's all you need: link 
against the module you want.  BUT, if you want to try to link against 
the static library (and now I'm talking from memory (it's been a year 
since I tried to do that, and I don't remember the result, I only 
remember a bunch of errors)), you'll need to know which libraries you 
need, which is the magic of pkg-config.

>> If you can't install that file in every binary package, you may
>> create a new binary package that only contains the .pc file,
>> let's say libopencv-pc, and make all packages depend on it.
> 
> This sounds overly complicated to me. I think we should move all 
> development files into one libopencv-dev if we want to fix this.
> But that's choice of the maintainers.
Moving everything into libopencv-dev would create a very big package 
when developers may not need all of opencv (I for example only depend on 
a few modules to build my programs).  One thing that I love of Debian 
packages is that they tend to be very modular compared to other distros. 
  Please don't put everything in one single pkg :-).

Thanks!

Cheers,

Alex

-- 
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/