fix(version): go install reports the module version, not 0.0.0-dev

internal/version/version.go

@@ -11,16 +11,42 @@ var Version = "0.0.0-dev"
 // devVersion is the source default, present when no release version was stamped in.
 const devVersion = "0.0.0-dev"
 
+// released returns the release version this binary carries, or "" when it is an
+// unstamped development build. A goreleaser build sets Version through ldflags; a
+// `go install <module>@<version>` build does not, but Go records the module version in
+// the build info, so that is used as the fallback. "(devel)" is Go's placeholder for a
+// build from a local checkout and is treated as unversioned.
+func released() string {
+	if Version != devVersion {
+		return Version
+	}
+	if bi, ok := debug.ReadBuildInfo(); ok {
+		return moduleVersion(bi.Main.Version)
+	}
+	return ""
+}
+
+// moduleVersion returns v when it is a usable module version, or "" for an absent
+// version or Go's "(devel)" placeholder (a build from a local checkout).
+func moduleVersion(v string) string {
+	if v == "" || v == "(devel)" {
+		return ""
+	}
+	return v
+}
+
 // IsDev reports whether this is an unstamped development build (no release version linked
 // in). A dev build keeps its durable state apart from a release build's, so an
-// in-progress schema change on a branch never touches a real installation.
-func IsDev() bool { return Version == devVersion }
+// in-progress schema change on a branch never touches a real installation. A build
+// installed with `go install ...@<version>` is a real release, not a dev build.
+func IsDev() bool { return released() == "" }
 
-// String returns a human-readable version, appending the VCS revision when the
-// binary was built from a git checkout and no explicit version was set.
+// String returns a human-readable version: the release version when one is present,
+// otherwise the source default with the VCS revision appended when the binary was built
+// from a git checkout.
 func String() string {
-	if Version != devVersion {
-		return Version
+	if v := released(); v != "" {
+		return v
 	}
 	if bi, ok := debug.ReadBuildInfo(); ok {
 		for _, s := range bi.Settings {

internal/version/version_test.go

@@ -13,3 +13,33 @@ func TestIsDevOnUnstampedBuild(t *testing.T) {
 		t.Fatal("IsDev() = false for an unstamped build, want true")
 	}
 }
+
+// TestStampedVersionWins confirms a release version linked in through ldflags is reported
+// verbatim and is not treated as a development build.
+func TestStampedVersionWins(t *testing.T) {
+	old := Version
+	defer func() { Version = old }()
+	Version = "v9.9.9"
+	if got := String(); got != "v9.9.9" {
+		t.Fatalf("String() = %q, want v9.9.9", got)
+	}
+	if IsDev() {
+		t.Fatal("IsDev() = true for a stamped build, want false")
+	}
+}
+
+// TestModuleVersionFallback confirms the `go install <module>@<version>` path: when no
+// release version is stamped through ldflags, a real module version from the build info
+// is used, while an absent version or Go's "(devel)" placeholder is not.
+func TestModuleVersionFallback(t *testing.T) {
+	for in, want := range map[string]string{
+		"v0.1.1":     "v0.1.1",
+		"v1.2.3-rc1": "v1.2.3-rc1",
+		"(devel)":    "",
+		"":           "",
+	} {
+		if got := moduleVersion(in); got != want {
+			t.Errorf("moduleVersion(%q) = %q, want %q", in, got, want)
+		}
+	}
+}