On Sun, Aug 14, 2016 at 11:49:28AM -0700, Chris Marusich wrote:
> Leo Famulari <leo@famulari.name> writes:
> 
> >> >> +  #:use-module ((guix licenses)
> >> >> +                #:select (gpl2+ bsd-3))
> >> >
> >> > Do we need to use #:select here? How about using a license prefix? What
> >> > are the pros and cons?
> >
> > I'll leave this as is.
> 
> Oh, sorry, I missed this comment.  What is the difference?  I'm
> unfamiliar with what it means to "use a license prefix"; where can I
> find more info about that?

Generally, we have the problem of using different variables named
'expat', 'zlib', 'openssl', and possibly others. For those 3, there are
both package and license variables sharing the name.

So, if we want to refer to both the package and license variables of,
for example, expat, we have to distinguish them somehow. So, we
sometimes "prefix" the licenses when they are used, to distinguish them
from the packages.

There is a good example in 'gnu/packages/admin.scm'. Check line 33,
where the license module is imported:

33   #:use-module ((guix licenses) #:prefix license:)

and line 107, where you can see it in action:

107     (license license:gpl2+)))

Using #:select to only import specific licenses can help, but you still
have a problem when it's time to #:select the expat license.