[bug#28690] provide a lib output for boost

[Thomas Danckaert]

Dave Love <address@hidden> writes:

> I mentioned elsewhere noticing the large size of boost in closures.
> I've now realized what the problem was with making a lib output, and
> done one, as below.  However, presumably it should have a dependency of
> out on lib for compatibility, and I don't know the right way to do that.

Yes, I've also noticed that, and also think it's worth to split the
package.

I don't think it's possible to have one output of a package depend on
another, though.  We could just add boost:lib to the inputs for every
package which relies on boost (except for packages which only rely on
header-only parts of boost)?

Another solution might be to turn the 2 outputs into 2 separate guix
packages, "boost" and "boost-libs", where "boost" only contains the
headers, and has "boost-libs" as a propagated-input.  I'm not sure if
this will do the right thing (i.e. make boost-libs available in the
build environment when boost is a regular input, but not propagate it
further), someone should try it out ;).

Thomas