go build fails on local packages resolving to underscore prefixed paths

[xbig...@gmail.com]

I work on a project with the following structure, and have been developing it for months without any problem.

project/
    module1/
        module1.go
    module2/
        module2.go
        submodule1/
            submodule1.go
        submodule2/
            submodule2.go
    module3/
        module3.go

As of today, when I execute `go build ./...` at the top of the project the following errors result.

module3/module3.go:98: undefined: submodule2.FunctionInSubmodule2

The code in question resembles the following.

package module3

import "github.com/company/project/module2/submodule2"

func Execute() {
    err := submodule2.FunctionInSubmodule2()
    if err != nil{
        panic(err)
    }
}

The only change I noticed starting today was the output from go build.

Previously, the package names were listed during the build, but now I am seeing them as paths in my home directory. These paths are also prefixed with underscores.

$ go build ./...
# _/home/myuser/myworkspace/project/source/backend/sundor

module3/module3.go:98: undefined: submodule2.FunctionInSubmodule2

Note that `/home/myuser/myworkspace/project` in a symlink to `$GOPATH/src/github.com/company/project`

I am running go 1.5.1 on Ubuntu 14.04.

I don't remember ever seeing the underscores in my imports before. Is this an issue anyone else has encountered. Any suggestions are appreciated.

[Dave Cheney]

The go tool thinks GOPATH is not set or is incorrect. You must not use symlinks inside or around your GOPATH as symlinks allow the source of a package to appear at multiple locations and the go tool will act to avoid that, leaving you in the situation you find.

[xbig...@gmail.com]

Thank you so much! That was exactly the problem. When I cd into the directory explicitly (not the symlink), the build works as expected. Strange that I've been developing multiple projects this way since go 1.3 without any trouble. Thanks again.