Use getBinPath for VSCODE_GOTOOLS instead of modifying GOPATH

src/goInstallTools.ts

@@ -14,8 +14,7 @@ import { showGoStatus, hideGoStatus } from './goStatus';
 import { getBinPath } from './goPath';
 
 let channel = vscode.window.createOutputChannel('Go');
-let toolsGoPath = process.env['VSCODE_GOTOOLS'];
-
+
 let tools: { [key: string]: string } = {
 	gorename: 'golang.org/x/tools/cmd/gorename',
 	gopkgs: 'github.com/tpng/gopkgs',
@@ -34,6 +33,7 @@ export function installTool(tool: string) {
 
 	// If the VSCODE_GOTOOLS environment variable is set, use 
 	// its value as the GOPATH for the "go get" child precess.
+	let toolsGoPath = process.env['VSCODE_GOTOOLS'];
 	let env = Object.assign({}, process.env);
 	if(toolsGoPath) {
 		env['GOPATH'] = toolsGoPath;
@@ -68,12 +68,6 @@ export function setupGoPathAndOfferToInstallTools() {
 		});
 		return;
 	}
-
-	// If the VSCODE_GOTOOLS environment variable is set, 
-	// append its value to the process' GOPATH.
-	if(toolsGoPath) {
-		process.env['GOPATH'] = process.env['GOPATH'] + path.delimiter + toolsGoPath;
-	}
 
 	let keys = Object.keys(tools);
 	Promise.all(keys.map(tool => new Promise<string>((resolve, reject) => {

src/goPath.ts

@@ -16,7 +16,16 @@ export function getBinPath(binname: string) {
 	binname = correctBinname(binname);
 	if (binPathCache[binname]) return binPathCache[binname];
 
-	// First search each GOPATH workspace's bin folder
+	// First check VSCODE_GOTOOLS' bin folder
+	if (process.env['VSCODE_GOTOOLS']) {
+		let binpath = path.join(process.env['VSCODE_GOTOOLS'], 'bin', binname);
+		if (fs.existsSync(binpath)) {
+			binPathCache[binname] = binpath;
+			return binpath;
+		}
+	}
+
+	// Then search each GOPATH workspace's bin folder
 	if (process.env['GOPATH']) {
 		let workspaces = process.env['GOPATH'].split(path.delimiter);
 		for (let i = 0; i < workspaces.length; i++) {