build.Import doesn't find some vendored packages

[Travis Beauvais]

I'm working with build.Import to discover package dependencies and am having an issue where it find some packages in the vendor folder but not others. Specifically, golang/x packages. I have both oauth2 and tools in the vendor folder but it only finds oauth2 and instead finds the $GOPATH tools install. Both oauth2 and tools are installed in $GOPATH and vendor folder. tools is the only package that doesn't get found in vendor.

My code is

        wd, _ := os.Getwd() // need to pass in wd as src directory to import otherwise it always find global installs

        pkg, _ := build.Import("golang.org/x/tools", wd, build.FindOnly)

        fmt.Println("ImportPath =", pkg.ImportPath)

        pkg, _ = build.Import("golang.org/x/oauth2", wd, build.FindOnly)

        fmt.Println("ImportPath =", pkg.ImportPath)

Here is my directory structure which also shows both oauth2 and tools installed in the vendor folder and the output of the above code.

        /hom/src/github.com/travis/play • master > ls -la vendor/golang.org/x/

        drwxr-xr-x   4 travis  staff   136 May  1 14:57 .

        drwxr-xr-x   3 travis  staff   102 May  1 13:39 ..

        drwxr-xr-x  33 travis  staff  1122 May  1 13:39 oauth2

        drwxr-xr-x  24 travis  staff   816 May  1 14:56 tools

        /home/src/github.com/travis/play • master > go run vendor.go

        ImportPath = golang.org/x/tools

        ImportPath = github.com/travis/play/vendor/golang.org/x/oauth2

Am I missing something?

[Travis Beauvais]

I think I've figured out why this is happening but it still kind of weird.

golang/x/tools is technically a package. It's just a folder. If I change the code to try and import golang.org/x/tools/go/vcs it finds the vendored version.

What's weird in my opinion is that it doesn't consider the vendored version a valid package when importing golang.org/x/tool, why does it allow the $GOPATH version? Shouldn't it return an error instead (I know I am swallowing the errors in my sample but I have checked them and none of the calls to build.Import return an error)?

[Travis Beauvais]

Sorry, that should say "golang.org/x/tools is technically NOT a package"