gh-109276: regrtest: add WORKER_FAILED state (#110148)

Rename WORKER_ERROR to WORKER_BUG. Add WORKER_FAILED state: it does
not stop the manager, whereas WORKER_BUG does.

Change also TestResults.display_result() order: display failed tests
at the end, the important important information.

WorkerThread now tries to get the signal name for negative exit code.

1 files changed, 12 insertions, 6 deletions

diff --git a/Lib/test/libregrtest/result.py b/Lib/test/libregrtest/result.py
index bf88526..d6b0d5a 100644
--- a/Lib/test/libregrtest/result.py
+++ b/Lib/test/libregrtest/result.py
@@ -19,7 +19,8 @@ class State:
     ENV_CHANGED = "ENV_CHANGED"
     RESOURCE_DENIED = "RESOURCE_DENIED"
     INTERRUPTED = "INTERRUPTED"
-    MULTIPROCESSING_ERROR = "MULTIPROCESSING_ERROR"
+    WORKER_FAILED = "WORKER_FAILED"   # non-zero worker process exit code
+    WORKER_BUG = "WORKER_BUG"         # exception when running a worker
     DID_NOT_RUN = "DID_NOT_RUN"
     TIMEOUT = "TIMEOUT"
 
@@ -29,7 +30,8 @@ class State:
             State.FAILED,
             State.UNCAUGHT_EXC,
             State.REFLEAK,
-            State.MULTIPROCESSING_ERROR,
+            State.WORKER_FAILED,
+            State.WORKER_BUG,
             State.TIMEOUT}
 
     @staticmethod
@@ -42,14 +44,16 @@ class State:
             State.SKIPPED,
             State.RESOURCE_DENIED,
             State.INTERRUPTED,
-            State.MULTIPROCESSING_ERROR,
+            State.WORKER_FAILED,
+            State.WORKER_BUG,
             State.DID_NOT_RUN}
 
     @staticmethod
     def must_stop(state):
         return state in {
             State.INTERRUPTED,
-            State.MULTIPROCESSING_ERROR}
+            State.WORKER_BUG,
+        }
 
 
 @dataclasses.dataclass(slots=True)
@@ -108,8 +112,10 @@ class TestResult:
                 return f"{self.test_name} skipped (resource denied)"
             case State.INTERRUPTED:
                 return f"{self.test_name} interrupted"
-            case State.MULTIPROCESSING_ERROR:
-                return f"{self.test_name} process crashed"
+            case State.WORKER_FAILED:
+                return f"{self.test_name} worker non-zero exit code"
+            case State.WORKER_BUG:
+                return f"{self.test_name} worker bug"
             case State.DID_NOT_RUN:
                 return f"{self.test_name} ran no tests"
             case State.TIMEOUT: