ALTERNATIVES framework and multiple package versions question

[Bartek Krawczyk <bbartlomiej.mail%gmail.com@localhost>]

Hi all,
I've been struggling to find more information on the alternatives
framework. I understand what the file does in package directory but:
- is it intended to be completely ignored when pkg_alternatives is not
installed?
- shouldn't pkg_alternatives be a dependency for any packages using
ALTERNATIVES?

I am trying to restart my journey of creating pkgsrc packages and I am
working on a package requiring Go to build. When I install lang/go it
installs go14 (I understand it is required to build go115,  but why?)
and go115, however the binary installed /usr/pkg/bin is go115 which is
not found by gmake (the Makefile expects "go").
What is the proper way to handle packages with multiple versions?
- should pkg_alternatives be installed before to create a symlink from
go115 to go?
- should I patch the Makefile of my package to replace "go" with
"go115" - how do I then handle upgraded versions of Go from pkgsrc?
- is there a way to properly include current default version of go and
use it to build a package?
Questions are not specific to Go but I see that python is in a similar
situation? Also here I fail to understand why lang/python looks the
way it looks.

I'd appreciate any hints. Thanks.
-- 
Bartek Krawczyk