return true
	}
	for _, dotPath := range dotPaths {
		if strings.HasPrefix(arg, dotPath) {
			return true
		}
	}
	return false
}

// importDir is just an error-catching wrapper for build.ImportDir.
func importDir(dir string) *build.Package {
	pkg, err := build.ImportDir(dir, build.ImportComment)
	if err != nil {
		log.Fatal(err)
	}
	return pkg
}

		// change from one bootstrap toolchain to the next.
		// There are many internal packages that are listed in
		// bootstrapDirs and made into bootstrap copies based on the
		// current repo's source code. Those are fine; this is catching
		// references to internal packages in the older bootstrap toolchain.
		if strings.HasPrefix(path, "internal/") {
			fatalf("%s:%d: bootstrap-copied source file cannot import %s", srcFile, i+1, path)
		}

						return nil, index, false // collision
					}
					obj = m
					indirect = e.indirect
					continue // we can't have a matching field or interface method
				}
			}

			switch t := under(typ).(type) {
			case *Struct:
				// look for a matching field and collect embedded types
				for i, f := range t.fields {
					if f.sameId(pkg, name, foldCase) {
						assert(f.typ != nil)

		default:
			return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option (expected ssa/build/{debug,test,stats,dump=function_name})", flag, phase)
		}
		return ""
	}
	if phase == "genssa" {
		switch flag {
		case "dump":
			GenssaDump[valString] = true
		default:
			return fmt.Sprintf("Did not find a flag matching %s in -d=ssa/%s debug option (expected ssa/genssa/dump=function_name)", flag, phase)

				// defined type. This ensures that in a series of types, all matching against the
				// same type parameter, we infer a defined type if there is one, independent of
				// order. Type inference or assignment may fail, which is ok.
				// Selecting a defined type, if any, ensures that we don't lose the type name;
				// and since we have inexact unification, a value of equally named or matching
				// undefined type remains assignable (go.dev/issue/43056).

// (to avoid including a Go package clause doc comment),
// lines beginning with '// +build' are taken as build directives.
//
// The file is accepted only if each such line lists something
// matching the file. For example:
//
//	// +build windows linux
//
// marks the file as applicable only on Windows and Linux.
//
// If tags["*"] is true, then ShouldBuild will consider every

# go mod download vcstest/hello/v9 should fail, still print origin info
! go mod download -x -json vcs-test.golang.org/git/hello.git/v9@latest
cp stdout hellov9.json
stdout '"Version": "latest"'
stdout '"Error":.*no matching versions'
! stdout '"TagPrefix"'
stdout '"TagSum": "t1:47DEQpj8HBSa[+]/TImW[+]5JCeuQeRkm5NMpJWZG3hSuFU="'
stdout '"Ref": "HEAD"'
stdout '"Hash": "fc3a09f3dc5cfe0d7a743ea18f1f5226e68b3777"'
! stdout 'RepoSum'

[!net:github.com] stop

# The pseudo-version for a commit after a tag with a non-matching major version
# should instead be based on the last matching tag.
cp go.mod.orig go.mod
go mod edit -require github.com/pierrec/lz4@473cd7ce01a1
go list -m github.com/pierrec/lz4
stdout 'github.com/pierrec/lz4 v1.0.2-0.20190131084431-473cd7ce01a1'

			return fmt.Errorf("query %q requires a TagSum", query)
		}

	default:
		// The query may be "latest" or a version inequality or prefix.
		// Its result depends on the absence of higher tags matching the query,
		// not just the state of an individual ref or tag.
		if origin.TagSum == "" {
			return fmt.Errorf("query %q requires a TagSum", query)
		}
	}

	return repo.CheckReuse(ctx, origin)
}

each of which can match any string, including the empty string and
strings containing slashes. Such a pattern expands to all package
directories found in the GOPATH trees with names matching the
patterns.

To make common patterns more convenient, there are two special cases.
First, /... at the end of the pattern can match an empty string,