fix: log subagent swallowed errors in hook emission and restore paths

SebTardif · steipete · commit 3cfab5441be1 · 2026-05-25T00:35:54.000+01:00
Wire createSubsystemLogger into the two silent catch blocks that
discard errors during subagent lifecycle:

1. emitSubagentEndedHookOnce (subagent-registry-completion.ts):
   catch { return false } -&gt; catch (err) { log.warn(...); return false }

2. restoreSubagentRunsOnce (subagent-registry.ts):
   catch { /* ignore */ } -&gt; catch (err) { log.warn(...) }

Both paths now log the error message before continuing, providing
a diagnostic trail when hook emission or disk restore fails silently.

Signed-off-by: Sebastien Tardif &lt;sebtardif@ncf.ca&gt;
diff --git a/src/agents/subagent-registry-completion.ts b/src/agents/subagent-registry-completion.ts
@@ -1,3 +1,4 @@
+import { createSubsystemLogger } from "../logging/subsystem.js";
 import { getGlobalHookRunner } from "../plugins/hook-runner-global.js";
 import type { SubagentRunOutcome } from "./subagent-announce-output.js";
 import {
@@ -10,6 +11,8 @@ import {
 } from "./subagent-lifecycle-events.js";
 import type { SubagentRunRecord } from "./subagent-registry.types.js";
 
+const log = createSubsystemLogger("agents/subagent-registry-completion");
+
 export function runOutcomesEqual(
   a: SubagentRunOutcome | undefined,
   b: SubagentRunOutcome | undefined,
@@ -113,7 +116,10 @@ export async function emitSubagentEndedHookOnce(params: {
     params.entry.endedHookEmittedAt = Date.now();
     params.persist();
     return true;
-  } catch {
+  } catch (err) {
+    log.warn(
+      `failed to emit subagent_ended hook for run ${runId}: ${err instanceof Error ? err.message : String(err)}`,
+    );
     return false;
   } finally {
     params.inFlightRunIds.delete(runId);
diff --git a/src/agents/subagent-registry.ts b/src/agents/subagent-registry.ts
@@ -646,8 +646,10 @@ function restoreSubagentRunsOnce() {
     // Cold-start restore path: queue the same recovery pass that restart
     // startup also uses so resumed children are handled through one seam.
     scheduleSubagentOrphanRecovery();
-  } catch {
-    // ignore restore failures
+  } catch (err) {
+    log.warn(
+      `failed to restore subagent runs from disk: ${err instanceof Error ? err.message : String(err)}`,
+    );
   }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -646,8 +646,10 @@ function restoreSubagentRunsOnce() {`
`646`	`646`	`// Cold-start restore path: queue the same recovery pass that restart`
`647`	`647`	`// startup also uses so resumed children are handled through one seam.`
`648`	`648`	`scheduleSubagentOrphanRecovery();`
`649`		`- } catch {`
`650`		`- // ignore restore failures`
	`649`	`+ } catch (err) {`
	`650`	`+ log.warn(`
	`651`	+ `failed to restore subagent runs from disk: ${err instanceof Error ? err.message : String(err)}`,
	`652`	`+ );`
`651`	`653`	`}`
`652`	`654`	`}`
`653`	`655`