1 files changed, 52 insertions, 0 deletions
diff --git a/app/tests/test_backends_servers.py b/app/tests/test_backends_servers.py
index 61897d4..4065a34 100644
--- a/app/tests/test_backends_servers.py
+++ b/app/tests/test_backends_servers.py
@@ -1,9 +1,11 @@
 """Tests for the server lifecycle module (backends/servers.py)."""
 
+import io
 import os
 import signal
 import tempfile
 import unittest
+from contextlib import redirect_stdout
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
@@ -118,6 +120,56 @@ class StartTests(unittest.TestCase):
         # Pid file cleaned up after early exit.
         self.assertFalse((self.dir / "test-server.pid").exists())
 
+    def test_exited_event_carries_a_known_crash_hint(self):
+        """The exited event's log tail is scanned for known signatures."""
+        (self.dir / "test-server.log").write_text(
+            "triton.compiler.errors.CompilationError:\n"
+            'ValueError("type fp8e4nv not supported in this architecture. '
+            'The supported fp8 dtypes are")\n', encoding="utf-8")
+        proc = MagicMock()
+        proc.pid = 99
+        proc.poll.return_value = 1
+        events = []
+        with patch.object(servers, "LOG_DIR", self.dir), \
+                patch("subprocess.Popen", return_value=proc), \
+                patch("backends.common.server_running", return_value=False), \
+                patch("time.sleep"):
+            ok = servers.start(self.spec, progress=events.append)
+        self.assertFalse(ok)
+        exited = next(e for e in events if e.get("kind") == "exited")
+        self.assertIn("FP8", exited["hint"])
+        self.assertIn("8.9", exited["hint"])
+
+    def test_exited_event_has_no_hint_for_unknown_crashes(self):
+        proc = MagicMock()
+        proc.pid = 99
+        proc.poll.return_value = 1
+        events = []
+        with patch.object(servers, "LOG_DIR", self.dir), \
+                patch("subprocess.Popen", return_value=proc), \
+                patch("backends.common.server_running", return_value=False), \
+                patch("time.sleep"):
+            servers.start(self.spec, progress=events.append)
+        exited = next(e for e in events if e.get("kind") == "exited")
+        self.assertIsNone(exited["hint"])
+
+    def test_boot_hint_reads_the_log_tail(self):
+        self.assertIsNone(servers._boot_hint(["everything fine"]))
+        self.assertIn("FP8", servers._boot_hint(
+            ["x", 'ValueError("type fp8e4nv not supported in this '
+            'architecture")', "y"]))
+        self.assertIsNone(servers._boot_hint([]))
+
+    def test_console_progress_prints_the_hint(self):
+        out = io.StringIO()
+        with redirect_stdout(out):
+            servers._console_progress({
+                "kind": "exited", "name": "test", "returncode": 1,
+                "log_tail": ["boom"], "hint": "FP8 needs compute "
+                                              "capability 8.9+"})
+        self.assertIn("hint: FP8 needs compute capability 8.9+",
+                      out.getvalue())
+
     def test_returns_false_on_timeout(self):
         proc = MagicMock()
         proc.pid = 7