diff --git a/src/resources/extensions/gsd/auto-worktree.ts b/src/resources/extensions/gsd/auto-worktree.ts
index c4aefe621..1ccac09e7 100644
--- a/src/resources/extensions/gsd/auto-worktree.ts
+++ b/src/resources/extensions/gsd/auto-worktree.ts
@@ -2013,8 +2013,8 @@ export function mergeMilestoneToMain(
     let preTeardownBranch: string | null = null;
     try {
       preTeardownBranch = nativeGetCurrentBranch(worktreeCwd);
-    } catch {
-      // Branch detection failure is non-fatal — skip the auto-commit to be safe
+    } catch (err) {
+      debugLog("mergeMilestoneToMain", { phase: "pre-teardown-branch-detect-failed", error: String(err) });
     }
     const isOnMilestoneBranch = preTeardownBranch === milestoneBranch;