)

// dirInModule locates the directory that would hold the package named by the given path,
// if it were in the module with module path mpath and root mdir.
// If path is syntactically not within mpath,
// or if mdir is a local file tree (isLocal == true) and the directory
// that would hold path is in a sub-module (covered by a go.mod below mdir),
// dirInModule returns "", false, nil.
//

					// within module "std" either.
					return "", errPkgIsBuiltin
				}
				return pkg, nil
			}

			pkg := pathpkg.Join(mainModulePrefix, suffix)
			if _, ok, err := dirInModule(pkg, mainModulePrefix, modRoot, true); err != nil {
				return "", err
			} else if !ok {
				// This main module could contain the directory but doesn't. Other main