Comment 1:

go env doesn't print some variables like GODEBUG either.
My personal opinion is we should not add this to the go env output
* GOMAXPROCS isn't forever, it might be removed or changed in the future
* I personally don't want to see it popularized any more than it has been 
* I believe that if setting GOMAXPROCS is required it shouldn't be done as part of a
login session, but when launching a specific Go binary, ie env GOMAXPROCS=2 myapp

Comment 2:

there are other runtime environment variables that `go env` doesn't print, e.g.
GODEBUG, GOTRACEBACK.
I don't think `go env` should print GOMAXPROCS.
GOPATH is entirely different, as it applies directly to go tool itself, and it's
not a runtime environment variable.

Comment 3:

yeah, the last point from Dave is especially important.
One shouldn't set GOMAXPROCS globally: it's a case-by-case setting.

Comment 4:

Makes sense. I'm convinced. Can you close this issue if you can? (I can't.)

Comment 5:

Status changed to WorkingAsIntended.