[bug#28690] provide a lib output for boost

[Roel Janssen]

Dave Love writes:

> [Sorry, this got buried.]
>
> Roel Janssen <address@hidden> writes:
>
>> Boost consists of various modules or components.  Some of these are
>> "header-only".  How does this patch handle that?
>
> The headers are in the main package, compatibly with the current
> situation if you're not doing anything which depends on the runtime.
>
>> If I were to install the "lib" output, could I then compile a C++
>> program that uses a header-only part of Boost?
>
> No.  The point of the patch is not to pay the price of the headers in
> space at run time.
>
> I think you should be able to use just "boost" as an input, and build
> things which require the runtime (certainly for compatibility), hence my
> question about the right way to make the dependency.
>
> [I'm not convinced by Guix' convention for packaging compared with
> having the development sub-packages of other distributions, at least if
> you're trying to stop the closure of one package being comparable with
> the size I expect of an entire HPC node image.]

Ah, now I understand.  We could indeed reduce the size of the closure
by having a small boost package that contains all the run-time
references needed by programs.

Thanks!

Kind regards,
Roel Janssen