A default checkout is left uncompared when either the fetch or the
ls-remote default-branch lookup fails, but its row always blamed the
fetch, contradicting the repository's Failures row.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

@@ -250,3 +250,3 @@
     case "manual-review": {
       if (comparison !== null && !comparison.fresh) {
-        if (fetched) return { aheadBehind: formatAheadBehind(comparison), why: "not compared: origin fetch failed" };
+        if (fetched) return { aheadBehind: formatAheadBehind(comparison), why: "not compared: origin fetch or default-branch lookup failed" };

@@ -389,0 +425,4 @@
+      ],
+    }),
+  );
+  assert.ok(markdown.includes("| app | main | +0/-5 | cached comparison, 4 uncommitted files; not re-checked: fetch failed |"));

@@ -179,0 +181,4 @@
+  if (repository.fatalError !== undefined) return "audit aborted";
+  const causes: string[] = [];
+  if (repository.fetch.ok !== true) causes.push("fetch failed");
+  if (repository.defaultBranchResolution.remoteHeadOk !== true) causes.push("could not read the server's default branch");

@@ -179,0 +182,4 @@
+  const causes: string[] = [];
+  if (repository.fetch.ok !== true) causes.push("fetch failed");
+  if (repository.defaultBranchResolution.remoteHeadOk !== true) causes.push("could not read the server's default branch");
+  return causes.join(", and ") || "comparison not refreshed";

@@ -185,3 +197,3 @@
   if (comparison.ahead > 0) return `${count(comparison.ahead, "local commit")} not pushed${dirtyNote}`;
   if (dirty > 0 && comparison.behind > 0) {
-    return `behind; uncommitted changes (${count(dirty, "file")}) block the fast-forward: not deferred guidance, or upstream changed the same paths`;
+    return `behind; uncommitted changes (${count(dirty, "file")}) block the fast-forward: not all are AGENTS.md, .agents/, or submodule selector changes, or upstream changed the same paths`;

@@ -389,0 +426,4 @@
+    }),
+  );
+  assert.ok(markdown.includes("| app | main | +0/-5 | cached comparison, 4 uncommitted files; not re-checked: fetch failed |"));
+  assert.ok(markdown.includes("| app | could not read the server's default branch |"));

@@ -177,2 +177,4 @@
 
-function defaultNotCurrentReason(worktree: Worktree): string {
+// Why a fetched run left a repository's comparisons stale, worded as its Failures row; null on a cached run.
+// Only the first cause is named: the Failures table lists every one.
+function staleCause(repository: Repository, fetched: boolean): string | null {

@@ -179,0 +179,4 @@
+// Only the first cause is named: the Failures table lists every one.
+function staleCause(repository: Repository, fetched: boolean): string | null {
+  if (!fetched) return null;
+  if (repository.fatalError !== undefined) return "audit aborted";

@@ -179,0 +185,4 @@
+  return "no cause recorded";
+}
+
+function defaultNotCurrentReason(worktree: Worktree, staleCause: string | null): string {

@@ -185,3 +197,3 @@
   if (comparison.ahead > 0) return `${count(comparison.ahead, "local commit")} not pushed${dirtyNote}`;
   if (dirty > 0 && comparison.behind > 0) {
-    return `behind; uncommitted changes (${count(dirty, "file")}) block the fast-forward: not deferred guidance, or upstream changed the same paths`;
+    return `behind; uncommitted changes (${count(dirty, "file")}) block the fast-forward: not all are AGENTS.md, .agents/** at any depth, or first-party submodule selector changes; or upstream changed the same paths`;

@@ -388,0 +392,4 @@
+  assert.ok(markdown.includes("| app-y | not checked for removal: origin fetch or default-branch read failed |"));
+});
+
+test("a fetched run whose default-branch lookup failed does not blame the fetch", () => {

@@ -176,3 +176,3 @@
 }
 
-function defaultNotCurrentReason(worktree: Worktree): string {
+// Why a fetched run left a repository's comparisons stale, worded as its Failures row; null on a cached run.

@@ -185,3 +197,3 @@
   if (comparison.ahead > 0) return `${count(comparison.ahead, "local commit")} not pushed${dirtyNote}`;
   if (dirty > 0 && comparison.behind > 0) {
-    return `behind; uncommitted changes (${count(dirty, "file")}) block the fast-forward: not deferred guidance, or upstream changed the same paths`;
+    return `behind; uncommitted changes (${count(dirty, "file")}) block the fast-forward. A dirty checkout fast-forwards only when every changed path is AGENTS.md or under .agents/, at any depth, or first-party submodule metadata, and upstream changed none of those paths.`;