vendor: Update everything

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4620

vendor/github.com/onsi/gomega/gexec/build.go

@@ -3,12 +3,14 @@ package gexec
 import (
 	"errors"
 	"fmt"
+	"go/build"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"sync"
 )
 
@@ -21,17 +23,18 @@ var (
 Build uses go build to compile the package at packagePath.  The resulting binary is saved off in a temporary directory.
 A path pointing to this binary is returned.
 
-Build uses the $GOPATH set in your environment.  It passes the variadic args on to `go build`.
+Build uses the $GOPATH set in your environment. If $GOPATH is not set and you are using Go 1.8+,
+it will use the default GOPATH instead.  It passes the variadic args on to `go build`.
 */
 func Build(packagePath string, args ...string) (compiledPath string, err error) {
-	return doBuild(os.Getenv("GOPATH"), packagePath, nil, args...)
+	return doBuild(build.Default.GOPATH, packagePath, nil, args...)
 }
 
 /*
 BuildWithEnvironment is identical to Build but allows you to specify env vars to be set at build time.
 */
 func BuildWithEnvironment(packagePath string, env []string, args ...string) (compiledPath string, err error) {
-	return doBuild(os.Getenv("GOPATH"), packagePath, env, args...)
+	return doBuild(build.Default.GOPATH, packagePath, env, args...)
 }
 
 /*
@@ -41,6 +44,16 @@ func BuildIn(gopath string, packagePath string, args ...string) (compiledPath st
 	return doBuild(gopath, packagePath, nil, args...)
 }
 
+func replaceGoPath(environ []string, newGoPath string) []string {
+	newEnviron := []string{}
+	for _, v := range environ {
+		if !strings.HasPrefix(v, "GOPATH=") {
+			newEnviron = append(newEnviron, v)
+		}
+	}
+	return append(newEnviron, "GOPATH="+newGoPath)
+}
+
 func doBuild(gopath, packagePath string, env []string, args ...string) (compiledPath string, err error) {
 	tmpDir, err := temporaryDirectory()
 	if err != nil {
@@ -60,7 +73,7 @@ func doBuild(gopath, packagePath string, env []string, args ...string) (compiled
 	cmdArgs = append(cmdArgs, "-o", executable, packagePath)
 
 	build := exec.Command("go", cmdArgs...)
-	build.Env = append([]string{"GOPATH=" + gopath}, os.Environ()...)
+	build.Env = replaceGoPath(os.Environ(), gopath)
 	build.Env = append(build.Env, env...)
 
 	output, err := build.CombinedOutput()