code: func findSrcPaths(importPath string) (revelSourcePath, appSourcePath string) {
  	var (
  		gopaths = filepath.SplitList(build.Default.GOPATH)
  		goroot  = build.Default.GOROOT
  	)
  
  	if len(gopaths) == 0 {
  		RevelLog.Fatal("GOPATH environment variable is not set. " +
  			"Please refer to http://golang.org/doc/code.html to configure your Go environment.")
  	}
  
  	if ContainsString(gopaths, goroot) {
  		RevelLog.Fatalf("GOPATH (%s) must not include your GOROOT (%s). "+
  			"Please refer to http://golang.org/doc/code.html to configure your Go environment.",
  			gopaths, goroot)
  	}
  
  	appPkg, err := build.Import(importPath, "", build.FindOnly)
  	if err != nil {
  		RevelLog.Panic("Failed to import "+importPath+" with error:", "error", err)
  	}
  
  	revelPkg, err := build.Import(RevelImportPath, appPkg.Dir, build.FindOnly)
  	if err != nil {
  		RevelLog.Fatal("Failed to find Revel with error:", "error", err)
  	}
  
  	return revelPkg.Dir[:len(revelPkg.Dir)-len(RevelImportPath)], appPkg.SrcRoot
  }
docs: // findSrcPaths uses the "go/build" package to find the source root for Revel
  // and the app.