// the modRoots of the main modules.
	// modRoots != nil implies len(modRoots) > 0
	modRoots []string
	gopath   string
)

// EnterModule resets MainModules and requirements to refer to just this one module.
func EnterModule(ctx context.Context, enterModroot string) {
	MainModules = nil // reset MainModules
	requirements = nil
	workFilePath = "" // Force module mode
	modfetch.Reset()