tree 287aca5c78ac73f85c0037abbd176ac6d752ba4d
parent b72029adf3393d3635828fedcddd5ae7053d3250
author Dmitri Shuralyov <dmitshur@golang.org> 1614818143 -0500
committer Dmitri Shuralyov <dmitshur@golang.org> 1614960561 +0000

tour: look for content in module cache, not GOROOT/misc/tour

Tour content hasn't been available in GOROOT since Go 1.12¹, so stop
looking for it there.

A more useful fallback place to find tour content is the module cache.
When the golang.org/x/tour is in the build list, it will be found via
build.Import. It will not be found, however, when the tour binary is
run outside of a module. This situation is more common as of Go 1.16,
since the default GO111MODULE value changed to on². If the version of
the tour binary is known, access the content for that version from the
module cache.

In the future, this complex and imperfect machinery will be replaced
with simply embedding the needed files in the binary. We can't do that
quite yet (not without duplicating a lot of code) because Go 1.15 is
supported, and because Go 1.14 is used for deployment.

It's not neccessary to provide a custom socket.Environ (which served
to provide a custom GOPATH value pointing inside GOROOT; that path
is being removed here). Delete it along with some other unused code.

¹ https://golang.org/doc/go1.12#tour
² https://golang.org/doc/go1.16#modules

Fixes golang/go#44243.

Change-Id: Ia239700170b8614d21cafe9617b51dddf3e337d5
Reviewed-on: https://go-review.googlesource.com/c/tour/+/298529
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>