fix(macos): derive macOS version from Darwin kernel in fallback path

ajwan8998 · ajwan8998 · commit 6a0d688caaac · 2026-06-20T12:47:18.000+08:00
When sw_vers -productVersion is unavailable (CI, containers), derive the macOS version from the Darwin kernel major version using the known mapping (Darwin 12-24 = macOS major - 9). Darwin 25+ (macOS 26 Tahoe) no longer follows this formula, so return the raw kernel version. Fixes #95145
diff --git a/src/infra/os-summary.ts b/src/infra/os-summary.ts
@@ -15,7 +15,17 @@ const cachedOsSummaryByKey = new Map<string, OsSummary>();
 function macosVersion(): string {
   const res = spawnSync("sw_vers", ["-productVersion"], { encoding: "utf-8" });
   const out = normalizeOptionalString(res.stdout) ?? "";
-  return out || os.release();
+  if (out) return out;
+  // Fallback: derive macOS version from Darwin kernel (os.release()).
+  // Darwin 12-24 → macOS (major - 9), e.g. Darwin 24 = macOS 15
+  // Darwin 25+  → formula broke (macOS 26 Tahoe uses Darwin 25, not 16)
+  const release = os.release();
+  const major = parseInt(release.split(".")[0], 10);
+  if (!isNaN(major) && major >= 12 && major <= 24) {
+    return `${major - 9}.0`;
+  }
+  // Darwin 25+ or unknown: return raw version labeled clearly (#95145)
+  return release;
 }
 
 /** Resolves a compact OS label for diagnostics, logs, and environment summaries. */
diff --git a/src/infra/system-presence.ts b/src/infra/system-presence.ts
@@ -69,7 +69,13 @@ function initSelfPresence() {
       encoding: "utf-8",
     });
     const out = normalizeOptionalString(res.stdout) ?? "";
-    return out.length > 0 ? out : os.release();
+    if (out) return out;
+    const release = os.release();
+    const major = parseInt(release.split(".")[0], 10);
+    if (!isNaN(major) && major >= 12 && major <= 24) {
+      return `${major - 9}.0`;
+    }
+    return release;
   };
   const platform = (() => {
     const p = os.platform();
