We can offer better error messages to users in GOPATH mode. The Go
command has clear error messages indicating where it's looking for
its dependencies, so we can borrow these messages too.
The error message will look like this:
https://user-images.githubusercontent.com/5856771/100292862-bde8bb00-2f4f-11eb-9920-d945ee2c7e87.png
Change-Id: I39d367d0731ea5b7b7bb963699be3003b4fefe86
Reviewed-on: https://go-review.googlesource.com/c/tools/+/274119
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>