[codex] fix Linux OS release parsing

CHANGELOG.md

@@ -22,6 +22,11 @@
   and `networking.scope6` when no primary IPv6 address is available.
 - Mountpoint entries with no stat, device, filesystem, or option data are now
   omitted instead of rendering empty maps such as `mountpoints."/": {}`.
+- Linux `os.release` is now omitted when `/etc/os-release` has no
+  `VERSION_ID`, including Arch Linux; `BUILD_ID=rolling` is not treated as an
+  operating system release.
+- NixOS, Rocky Linux, and AlmaLinux `os.release` now split dotted
+  `VERSION_ID` values into `major` and `minor`, matching `os.distro.release`.
 
 ## v0.0.3 - 2026-06-18
 

Makefile

@@ -248,7 +248,7 @@ lima-docker-distro-facts: lima-docker-build-amd64
 			*) echo "missing expected os.distro.id for $$image" >&2; exit 2 ;; \
 		esac; \
 		echo "==> distro fact smoke $$image"; \
-		$(LIMACTL) shell '$(LIMA_DOCKER_INSTANCE)' -- sh -lc "set -eu; cd '$(CURDIR)'; out=\$$(docker run --rm --platform linux/amd64 -e CI=true -v \"\$$PWD/dist/facts-linux-amd64:/usr/local/bin/facts:ro\" $$image /usr/local/bin/facts --json os.name os.family os.distro.id os.distro.description os.release.major os.distro.release.major kernel.name virtual); printf '%s\n' \"\$$out\"; printf '%s\n' \"\$$out\" | grep -Eq '\"kernel.name\"[[:space:]]*:[[:space:]]*\"Linux\"'; printf '%s\n' \"\$$out\" | grep -Eq '\"os.distro.id\"[[:space:]]*:[[:space:]]*\"$$expected_id\"'" || exit $$?; \
+		$(LIMACTL) shell '$(LIMA_DOCKER_INSTANCE)' -- sh -lc "set -eu; cd '$(CURDIR)'; out=\$$(docker run --rm --platform linux/amd64 -e CI=true -v \"\$$PWD/dist/facts-linux-amd64:/usr/local/bin/facts:ro\" $$image /usr/local/bin/facts --json os.name os.family os.distro.id os.distro.description kernel.name virtual); printf '%s\n' \"\$$out\"; printf '%s\n' \"\$$out\" | grep -Eq '\"kernel.name\"[[:space:]]*:[[:space:]]*\"Linux\"'; printf '%s\n' \"\$$out\" | grep -Eq '\"os.distro.id\"[[:space:]]*:[[:space:]]*\"$$expected_id\"'" || exit $$?; \
 	done
 
 lima-docker-workloads: lima-docker-go-containers lima-docker-distro-facts

internal/engine/os.go

@@ -198,7 +198,10 @@ func currentMacOSModel(goos string, run commandRunner) string {
 
 func probeOSRelease(s *Session) any {
 	if runtime.GOOS == "windows" {
-		return currentWindowsOSRelease(s.cachedWindowsOSVersionInput())
+		if release := currentWindowsOSRelease(s.cachedWindowsOSVersionInput()); len(release) > 0 {
+			return release
+		}
+		return nil
 	}
 	return currentOSRelease(s, runtime.GOOS, s.readFile, s.commandOutput)
 }
@@ -225,7 +228,10 @@ func currentOSRelease(s *Session, goos string, readFile fileReader, run commandR
 		if release := specificLinuxOSRelease(id, readFile, run); len(release) > 0 {
 			return release
 		}
-		return parseLinuxOSRelease(string(data))
+		if release := parseLinuxOSRelease(string(data)); len(release) > 0 {
+			return release
+		}
+		return nil
 	case "freebsd":
 		versions := parseFreeBSDVersions(run("/bin/freebsd-version", "-k"), run("/bin/freebsd-version", "-ru"))
 		if versions.InstalledUserland != "" {
@@ -246,7 +252,10 @@ func currentOSRelease(s *Session, goos string, readFile fileReader, run commandR
 	case "darwin":
 		return parseDarwinOSRelease(run("uname", "-r"))
 	case "windows":
-		return currentWindowsOSRelease(windowsWMIOutput(run, "os", "OtherTypeDescription,ProductType,Version"))
+		if release := currentWindowsOSRelease(windowsWMIOutput(run, "os", "OtherTypeDescription,ProductType,Version")); len(release) > 0 {
+			return release
+		}
+		return nil
 	}
 	return s.cachedKernelRelease()
 }
@@ -711,7 +720,7 @@ func linuxOSReleaseMap(id, full string) map[string]any {
 		return debianReleaseMap(full)
 	}
 	switch strings.ToLower(id) {
-	case "mariner", "azurelinux", "linuxmint", "gentoo", "mageia":
+	case "mariner", "azurelinux", "linuxmint", "gentoo", "mageia", "nixos", "rocky", "almalinux":
 		return releaseHashFromString(full, false)
 	}
 	return map[string]any{"full": full, "major": full}

internal/engine/os_test.go

@@ -590,6 +590,34 @@ func TestParseLinuxOSRelease_padsDebianVersionIDLikeRubyResolver(t *testing.T) {
 	}
 }
 
+func TestParseLinuxOSRelease_splitsNixOSVersionID(t *testing.T) {
+	got := parseLinuxOSRelease("ID=nixos\nVERSION_ID=26.05\n")
+
+	want := map[string]any{"full": "26.05", "major": "26", "minor": "05"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("parseLinuxOSRelease() = %#v, want %#v", got, want)
+	}
+}
+
+func TestParseLinuxOSRelease_splitsRockyAndAlmaVersionID(t *testing.T) {
+	tests := []struct {
+		id string
+	}{
+		{id: "rocky"},
+		{id: "almalinux"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.id, func(t *testing.T) {
+			got := parseLinuxOSRelease("ID=" + tt.id + "\nVERSION_ID=9.8\n")
+
+			want := map[string]any{"full": "9.8", "major": "9", "minor": "8"}
+			if !reflect.DeepEqual(got, want) {
+				t.Fatalf("parseLinuxOSRelease() = %#v, want %#v", got, want)
+			}
+		})
+	}
+}
+
 func TestParseLinuxDistroOSRelease_trimsDebianMinorLeadingZero(t *testing.T) {
 	got := parseLinuxDistroOSRelease("ID=debian\nVERSION_ID=10.02\n")
 
@@ -1251,15 +1279,34 @@ func TestParseLinuxDistroOSRelease_normalizesSLESNameAndSAPID(t *testing.T) {
 func TestParseLinuxDistroOSRelease_normalizesArchLinuxName(t *testing.T) {
 	t.Parallel()
 
-	got := parseLinuxDistroOSRelease("NAME=\"Arch Linux\"\nID=arch\nPRETTY_NAME=\"Arch Linux\"\n")
+	got := parseLinuxDistroOSRelease("NAME=\"Arch Linux\"\nID=arch\nBUILD_ID=rolling\nPRETTY_NAME=\"Arch Linux\"\n")
 	if got.Name != "Archlinux" {
 		t.Fatalf("parseLinuxDistroOSRelease().Name = %q, want Archlinux", got.Name)
 	}
+	if len(got.Release) != 0 || got.ReleaseKnown {
+		t.Fatalf("parseLinuxDistroOSRelease().Release = %#v, ReleaseKnown = %v, want no release from BUILD_ID", got.Release, got.ReleaseKnown)
+	}
 	if name := osName("linux", got); name != "Archlinux" {
 		t.Fatalf("osName(linux, arch) = %q, want Archlinux", name)
 	}
 }
 
+func TestCurrentOSRelease_omitsArchRollingBuildID(t *testing.T) {
+	t.Parallel()
+
+	readFile := func(path string) ([]byte, error) {
+		if path != "/etc/os-release" {
+			return nil, os.ErrNotExist
+		}
+		return []byte("NAME=\"Arch Linux\"\nPRETTY_NAME=\"Arch Linux\"\nID=arch\nBUILD_ID=rolling\n"), nil
+	}
+
+	got := currentOSRelease(testSession, "linux", readFile, func(string, ...string) string { return "" })
+	if got != nil {
+		t.Fatalf("currentOSRelease(testSession, arch) = %#v, want nil because BUILD_ID is not a release", got)
+	}
+}
+
 func TestParseLinuxDistroOSRelease_normalizesManjaroLinuxName(t *testing.T) {
 	t.Parallel()