go vendor_path doesn't work

The doc of vendor_path says “Packages in these directories are allowed to be imported given just the relative path to the package”. However, when I tried to import a third-party package in the vendor/ directory configured by vendor_path, buck couldn’t import the package.

This is my .buckconfig file:

[go]
  vendor_path = ./vendor

This is my BUCK file:

go_test(
  name='command_test',
  srcs=['command_test.go']
)

This is the command_test.go file:

package main

import (
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestName(t *testing.T) {
	assert.Equal(t, "name", "name")
}

When I ran buck test //:command_test, buck said:

command_test.go:6:2: can't find import: "github.com/stretchr/testify/assert"

However, the package exists in vendor/github.com/stretchr/testify/assert/

[linzhp]

Now I see the reason. I have package_name='github.com/stretchr/testify/assert' in the BUCK file. So it overrides the vendor_path. Thanks for the help!

[nemith]

If you turn on verbose output you can see exactly what Buck is doing.

NO_BUCKD=1 buck build //gobin/... -v 3 
Guessing 2645680beb2bdbbb4cef865a248234eb96102568 as the last one used version.
2018-01-03 10:10:41,181 [WARNING][buck_tool.py:469] Not using buckd because NO_BUCKD is set.
PARSING BUCK FILES... 1.3s (100%)
CREATING ACTION GRAPH: FINISHED IN 0.1s
verify_symlink_tree
verify_symlink_tree
verify_symlink_tree
rm -f -r buck-out/bin/gobin/__gobin#transitive-symlink-tree__tree
rm -f -r buck-out/bin/third-party/go/github.com/pkg/errors/__errors#linux_amd64,symlink-tree__tree
rm -f -r buck-out/bin/gobin/__gobin#compile,linux_amd64,symlink-tree__tree
mkdir -p buck-out/bin/gobin/__gobin#compile,linux_amd64,symlink-tree__tree
mkdir -p buck-out/bin/gobin/__gobin#transitive-symlink-tree__tree
mkdir -p buck-out/bin/third-party/go/github.com/pkg/errors/__errors#linux_amd64,symlink-tree__tree
link tree @ buck-out/bin/gobin/__gobin#compile,linux_amd64,symlink-tree__tree
link tree @ buck-out/bin/gobin/__gobin#transitive-symlink-tree__tree
link tree @ buck-out/bin/third-party/go/github.com/pkg/errors/__errors#linux_amd64,symlink-tree__tree
mkdir -p buck-out/gen/third-party/go/github.com/pkg/errors/errors#linux_amd64
BUILT 1/7 JOBS 0.1s //gobin:gobin#transitive-symlink-tree
(cd /home/bbennett/bucktest && GOROOT=/usr/lib/golang GOOS=linux GOARCH=amd64 /usr/lib/golang/pkg/tool/linux_amd64/compile -p third-party/go/github.com/pkg/errors -pack -trimpath /home/bbennett/bucktest -nolocalimports -o buck-out/gen/third-party/go/github.com/pkg/errors/errors#linux_amd64/errors.a -I /home/bbennett/bucktest/buck-out/bin/third-party/go/github.com/pkg/errors/__errors#linux_amd64,symlink-tree__tree -complete /home/bbennett/bucktest/third-party/go/github.com/pkg/errors/errors.go /home/bbennett/bucktest/third-party/go/github.com/pkg/errors/stack.go)
BUILT 2/7 JOBS 0.1s //third-party/go/github.com/pkg/errors:errors
BUILT 3/7 JOBS 0.1s //gobin:gobin#compile,linux_amd64,symlink-tree
BUILT 4/7 JOBS 0.1s //third-party/go/github.com/pkg/errors:errors#linux_amd64,symlink-tree
mkdir -p buck-out/gen/gobin/gobin#compile,linux_amd64
(cd /home/bbennett/bucktest && GOROOT=/usr/lib/golang GOOS=linux GOARCH=amd64 /usr/lib/golang/pkg/tool/linux_amd64/compile -p main -pack -trimpath /home/bbennett/bucktest -nolocalimports -o buck-out/gen/gobin/gobin#compile,linux_amd64/gobin.a -I /home/bbennett/bucktest/buck-out/bin/gobin/__gobin#compile,linux_amd64,symlink-tree__tree -importmap 'github.com/pkg/errors=third-party/go/github.com/pkg/errors' -complete /home/bbennett/bucktest/gobin/main.go)
mkdir -p buck-out/gen/gobin/gobin
(cd /home/bbennett/bucktest && GOROOT=/usr/lib/golang GOOS=linux GOARCH=amd64 /usr/lib/golang/pkg/tool/linux_amd64/link -o buck-out/gen/gobin/gobin/gobin -buildmode exe -L /home/bbennett/bucktest/buck-out/bin/gobin/__gobin#transitive-symlink-tree__tree -extld /bin/g++ buck-out/gen/gobin/gobin#compile,linux_amd64/gobin.a)
BUILT 5/7 JOBS 0.1s //gobin:gobin#compile,linux_amd64
BUILT 6/7 JOBS 0.3s //third-party/go/github.com/pkg/errors:errors#linux_amd64
BUILT 7/7 JOBS 0.3s //gobin:gobin
DOWNLOADED 0 ARTIFACTS, 0.00 BYTES
BUILDING: FINISHED IN 2.8s (100%) 7/7 JOBS, 7 UPDATED, 42.9% CACHE MISS
BUILD SUCCEEDED

Specifically the compile command has imports mapped.

(cd /home/bbennett/bucktest && GOROOT=/usr/lib/golang GOOS=linux GOARCH=amd64 /usr/lib/golang/pkg/tool/linux_amd64/compile -p main -pack -trimpath /home/bbennett/bucktest -nolocalimports -o buck-out/gen/gobin/gobin#compile,linux_amd64/gobin.a -I /home/bbennett/bucktest/buck-out/bin/gobin/__gobin#compile,linux_amd64,symlink-tree__tree -importmap 'github.com/pkg/errors=third-party/go/github.com/pkg/errors' -complete /home/bbennett/bucktest/gobin/main.go)

Since it’s still hard to see -importmap 'github.com/pkg/errors=third-party/go/github.com/pkg/errors' which does the mapping to make the compiler happy. It’s not a really big feature but useful for us.