cmd/go: go get fails when GOPATH dir is relative

[techtonik]

When I specify GOPATH as relative to current dir, the go get command fails.

From https://github.com/syncthing/syncthing-cli/issues/12

$ mkdir .go
$ GOPATH=.go go get github.com/syncthing/syncthing-cli  
# github.com/AudriusButkevicius/cli
open .go/src/github.com/AudriusButkevicius/cli/app.go: No such file or directory
...
$ go version
go version go1.2.1 linux/amd64

I am using Ubuntu 14.04 packaged Go. http://packages.ubuntu.com/trusty/devel/golang-go

[bradfitz]

Instead of making relative paths work, we should probably just detect relative paths and fail earlier with a nice error.

[bradfitz]

/cc @robpike @rsc @adg for thoughts

[robpike]

Relative paths are dangerous when applied globally like this. I agree it should just be diagnosed.

[davecheney]

Seconded.

On Wed, Jun 17, 2015 at 3:41 AM, Rob Pike notifications@github.com wrote:

Relative paths are dangerous when applied globally like this. I agree it
should just be diagnosed.

—
Reply to this email directly or view it on GitHub
#11234 (comment).

[adg]

This was fixed by @broady in 239ec73. Note that the issue reporter's go version is 1.2.1.

[techtonik]

I am +1 on detecting error case. Is it possible to backport it to stable Debian/Ubuntu?

[bradfitz]

That is a question for Debian and/or Ubuntu, but not us. We don't do their packaging, nor do we maintain very old releases.