Indirect   bool             `json:",omitempty"` // module is only indirectly needed by main module
	Dir        string           `json:",omitempty"` // directory holding local copy of files, if any
	GoMod      string           `json:",omitempty"` // path to go.mod file describing module, if any
	GoVersion  string           `json:",omitempty"` // go version used in module

	return nil
}

// trimSubdir trims a single cache subdirectory.
func (c *DiskCache) trimSubdir(subdir string, cutoff time.Time) {
	// Read all directory entries from subdir before removing
	// any files, in case removing files invalidates the file offset
	// in the directory scan. Also, ignore error from f.Readdirnames,
	// because we don't care about reporting the error and we still
	// want to process any entries found before the error.

	//
	// We look for non-hidden .go files or subdirectories to determine whether
	// this is an existing project. Walking the tree for packages would be more
	// accurate, but could take much longer.
	empty := true
	files, _ := os.ReadDir(modRoot)
	for _, f := range files {
		name := f.Name()
		if strings.HasPrefix(name, ".") || strings.HasPrefix(name, "_") {

	check.objMap[obj] = d
	obj.setOrder(uint32(len(check.objMap)))
}

// filename returns a filename suitable for debugging output.
func (check *Checker) filename(fileNo int) string {
	file := check.files[fileNo]
	if pos := file.Pos(); pos.IsKnown() {
		// return check.fset.File(pos).Name()
		// TODO(gri) do we need the actual file name here?
		return pos.RelFilename()
	}
	return fmt.Sprintf("file[%d]", fileNo)
}

	if err != nil {
		return b.Shell(runAct).reportCmd("", "", output, err)
	}
	_, werr := w.Write(output)
	return werr
}

// WriteCoverMetaFilesFile writes out a summary file ("meta-files
// file") as part of the action function for the "writeCoverMeta"
// pseudo action employed during "go test -coverpkg" runs where there
// are multiple tests and multiple packages covered. It builds up a

// dirInModule returns "", false, nil.
//
// Otherwise, dirInModule returns the name of the directory where
// Go source files would be expected, along with a boolean indicating
// whether there are in fact Go source files in that directory.
// A non-nil error indicates that the existence of the directory and/or
// source files could not be determined, for example due to a permission error.

	realName, realSize := hdr.Name, hdr.Size

	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*
		// Handle sparse files.
		var spd sparseDatas
		var spb []byte
		if len(hdr.SparseHoles) > 0 {
			sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map
			sph = alignSparseEntries(sph, hdr.Size)

//
//	r <  0: p is before q
//	r == 0: p and q are the same position (but may not be identical)
//	r >  0: p is after q
//
// If p and q are in different files, p is before q if the filename
// of p sorts lexicographically before the filename of q.
func (p Pos) Cmp(q Pos) int {
	pname := p.RelFilename()
	qname := q.RelFilename()
	switch {
	case pname < qname:
		return -1

			if err != nil {
				ld.error(err)
				ld.exitIfErrors(ctx)
			}
		}

		// If the module's Go version omits go.sum entries for go.mod files for test
		// dependencies of external packages, avoid loading those files in the first
		// place.
		ld.skipImportModFiles = ld.Tidy && gover.Compare(goVersion, gover.TidyGoModSumVersion) < 0

	Failed       bool              // whether the action failed
	json         *actionJSON       // action graph information
	nonGoOverlay map[string]string // map from non-.go source files to copied files in objdir. Nil if no overlay is used.
	traceSpan    *trace.Span
}

// BuildActionID returns the action ID section of a's build ID.
func (a *Action) BuildActionID() string { return actionID(a.buildID) }