diff --git a/src/main/ipc/repos/proven-absence.test.ts b/src/main/ipc/repos/proven-absence.test.ts
index f0d377cb4f8..18335fdadb7 100644
--- a/src/main/ipc/repos/proven-absence.test.ts
+++ b/src/main/ipc/repos/proven-absence.test.ts
@@ -111,4 +111,16 @@ describe('proven-absence', () => {
     })
     expect(() => describeError(e)).not.toThrow()
   })
+
+  it('treats underscore errno families like EAI_* as authoritative', () => {
+    // EAI_AGAIN is a real libuv code; missing it let a transient DNS failure whose message
+    // quotes ENOENT read as proven absence.
+    for (const code of ['EAI_AGAIN', 'EAI_NONAME']) {
+      expect(
+        isProvenAbsent(
+          Object.assign(new Error("ENOENT: no such file or directory, stat '/x'"), { code })
+        )
+      ).toBe(false)
+    }
+  })
 })
diff --git a/src/main/ipc/repos/proven-absence.ts b/src/main/ipc/repos/proven-absence.ts
index 36daa6f6b5d..247c118d6b1 100644
--- a/src/main/ipc/repos/proven-absence.ts
+++ b/src/main/ipc/repos/proven-absence.ts
@@ -7,9 +7,14 @@ const ENOTDIR_MESSAGE = /^ENOTDIR: not a directory\b/
 
 // Why shape rather than a fixed list: EVERY real errno is authoritative, not just the two we care
 // about — an EACCES or ELOOP is a definitive non-absence answer even when the message quotes
-// ENOENT. But a wrapper attaching a domain string (`REMOTE_FS_ERROR`) is not an errno and must not
-// suppress the message fallback, which is the only classification path over the SSH relay.
-const ERRNO_NAME = /^E[A-Z0-9]+$/
+// ENOENT. Underscores are required: `EAI_AGAIN`/`EAI_NONAME` are real libuv codes, and missing them
+// let a transient DNS failure fall through to the message and read as proven absence.
+//
+// An E-prefixed code we do not recognise is therefore treated as an errno, i.e. NOT absence. That
+// biases toward refusing, which is the safe direction for this helper. Only a code that is not
+// errno-shaped at all (`REMOTE_FS_ERROR`, or the relay's numeric -32000) falls through to the
+// message — the only classification path that survives the SSH relay.
+const ERRNO_NAME = /^E[A-Z0-9_]+$/
 
 /** Whether a failed probe proves the path is absent. Never throws. */
 export function isProvenAbsent(error: unknown): boolean {
diff --git a/src/main/runtime/orca-runtime.ts b/src/main/runtime/orca-runtime.ts
index db2651c8270..18902a58cdb 100644
--- a/src/main/runtime/orca-runtime.ts
+++ b/src/main/runtime/orca-runtime.ts
@@ -1278,7 +1278,7 @@ import {
   LEFTOVER_GIT_DIR_RETRY_HINT,
   repositoryCheckUnavailableError
 } from '../ipc/repos/repository-creation-messages'
-import { isProvenAbsent } from '../ipc/repos/proven-absence'
+import { describeError, isProvenAbsent } from '../ipc/repos/proven-absence'
 import { getWorktreeWatcherRemoval } from '../ipc/worktree-watcher-removal'
 import { acquireWatcherRemovalGate } from '../ipc/watcher-removal-gate'
 import {
@@ -23925,7 +23925,7 @@ export class OrcaRuntimeService {
           // as "no failure" and fail open into `git init`.
           if (!isProvenAbsent(error)) {
             gitProbeFailed = true
-            gitProbeFailure = error instanceof Error ? error.message : String(error)
+            gitProbeFailure = describeError(error)
           }
           return null
         })