# For this module, Go 1.17 prunes out a (transitive and otherwise-irrelevant)
# requirement on a retracted higher version of a dependency.
# However, when Go 1.16 reads the same requirements from the go.mod file,
# it does not prune out that requirement, and selects the retracted version.
#
# The Go 1.16 module graph looks like:
#
# m ---- lazy v0.1.0 ---- requireincompatible v0.1.0 ---- incompatible v2.0.0+incompatible
# |        |

// CheckRetractions returns an error if module m has been retracted by
// its author.
func CheckRetractions(ctx context.Context, m module.Version) (err error) {
	defer func() {
		if retractErr := (*ModuleRetractedError)(nil); err == nil || errors.As(err, &retractErr) {
			return
		}
		// Attribute the error to the version being checked, not the version from

# For this module, Go 1.17 prunes out a (transitive and otherwise-irrelevant)
# requirement on a retracted higher version of a dependency.
# However, when Go 1.16 reads the same requirements from the go.mod file,
# it does not prune out that requirement, and selects the retracted version.
#
# The Go 1.16 module graph looks like:
#

					continue
				}
			}

			allowed := CheckAllowed
			if IsRevisionQuery(path, vers) || mode&ListRetracted != 0 {
				// Allow excluded and retracted versions if the user asked for a
				// specific revision or used 'go list -retracted'.
				allowed = nil
			}
			info, err := queryReuse(ctx, path, vers, current, allowed, reuse)
			if err != nil {
				var origin *codehost.Origin
				if info != nil {

# 'go install pkg@version' will only match a retracted version if it's
# explicitly requested.
env GO111MODULE=on
go list -m -versions example.com/cmd
! stdout v1.9.0
go list -m -versions -retracted example.com/cmd
stdout v1.9.0
go install example.com/cmd/a@latest
go version -m $GOPATH/bin/a$GOEXE

//
// require directives are not de-duplicated. That's left up to higher-level
// logic (MVS).
//
// retract directives are not de-duplicated since comments are
// meaningful, and versions may be retracted multiple times.
func (f *WorkFile) removeDups() {
	removeDups(f.Syntax, nil, &f.Replace)

// space-separated version list.
//
// The -retracted flag causes list to report information about retracted
// module versions. When -retracted is used with -f or -json, the Retracted
// field will be set to a string explaining why the version was retracted.
// The string is taken from comments on the retract directive in the
// module's go.mod file. When -retracted is used with -versions, retracted

	if err != nil {
		isRetracted = func(string) bool { return false }
	}

	// tagToVersion returns the version obtained by trimming tagPrefix from tag.
	// If the tag is invalid, retracted, or a pseudo-version, tagToVersion returns
	// an empty version.
	tagToVersion := func(tag string) (v string, tagIsCanonical bool) {
		if !strings.HasPrefix(tag, tagPrefix) {
			return "", false
		}

		downgraded = append(downgraded, r)
	}

	// The downgrades we computed above only downgrade to versions enumerated by
	// reqs.Previous. However, reqs.Previous omits some versions — such as
	// pseudo-versions and retracted versions — that may be selected as transitive
	// requirements of other modules.
	//
	// If one of those requirements pulls the version back up above the version

	37:  "signal 37",
	38:  "signal 38",
	39:  "signal 39",
	48:  "signal 48",
	49:  "signal 49",
	58:  "signal 58",
	59:  "CPU Failure Predicted",
	60:  "monitor mode granted",
	61:  "monitor mode retracted",
	62:  "sound completed",
	63:  "secure attention",
	255: "signal 255",