[bug#34752] Duplicated work (sorry!)

[Katherine Cox-Buday <cox.katherine.e@gmail.com>]

Hey Leo, I've just submitted patch 34887. I didn't realize your patch
existed until I had already submitted. I apologize, I don't contribute
to projects managed in this style enough to have the workflow
internalized :(

At any rate, my patch does much the same thing except that it leaves
1.11 in place as default. I did that for a couple of reasons:

- In organizations, it's very common for projects/teams to lag behind a
  bit the newest releases, and for people installing Go through Guix,
  it's nice to still have previous versions available. The Go team
  officially supports LATEST-2 releases, and I think we should consider
  doing the same.

- https://golang.org/doc/go1.12#gocache states that the build cache is
  now required. I saw that you were experimenting with setting the home
  directory to `/tmp`. The approach I considered taking was to modify
  the Go build-system to override the `GOCACHE` environmental variable
  when doing builds. Otherwise, any Go package will have to spoof the
  home directory.

Regarding your question about the test failures. I tried to resolve
these in 1.11 and the new ones that cropped up in 1.12. The issue is
that these "scripts" are effectively running in a custom little
script-engine that was custom built. I made some attempts at correcting
this which you can read about in patch 32768. You can find out more
about this scripting engine here:

https://github.com/golang/go/blob/release-branch.go1.12/src/cmd/go/testdata/script/README

-- 
Katherine