Fix the instability introduced in 3.1.1.

CHANGELOG.md

@@ -1,29 +1,30 @@
 # Version 3.2.0
 #### 6 June 2020
 
+- Fix crashes and hangs that could occur when using >1 subprocess due to a regression introduced in 3.1.1.
 - Add 'time' attributes to the `<testsuites>`, `<testsuite>`, and `<testcase>` fields in the Junit
   output for the `-j/--junit-report` output.  Contributed by @bkmd11 in #225. Resolves #208.
 
-# Version 3.1.4
+# Version 3.1.4 - Buggy! Please upgrade to >= 3.2.0!
 #### 7 May 2020
 
 - Fix class/module teardowns being ignored. They are now reported as errors as they should be. Resolves #223.
 - Fix dates in this changelog--I was still using last year! 😆
 
-# Version 3.1.3
+# Version 3.1.3 - Buggy! Please upgrade to >= 3.2.0!
 #### 5 May 2020
 
 - Fix crash that could occur when whitespace is in the path on Windows.
   Contributed by @bkmd11 in #222.
 
-# Version 3.1.2
+# Version 3.1.2 - Buggy! Please upgrade to >= 3.2.0!
 #### 4 May 2020
 
 - Fix a crash that could occur during cleanup on unusual filesystems on
   Python 2. Note that Python 2 is still not supported...but might as well fix
   stuff if it is easy to fix. :-) Resolves #221.
 
-# Version 3.1.1
+# Version 3.1.1 - Buggy! Please upgrade to >= 3.2.0!
 #### 22 April 2020
 
 - Fixed a hang that sometimes occurs in Python 3.8.0-3.8.2 due to a bug in upstream Python

green/runner.py

@@ -89,17 +89,17 @@ def run(suite, stream, args, testing=False):
 
         result.startTestRun()
 
+        # The call to toParallelTargets needs to happen before pool stuff so we can crash if there
+        # are, for example, syntax errors in the code to be loaded.
+        parallel_targets = toParallelTargets(suite, args.targets)
+        pool = LoggingDaemonlessPool(
+            processes=args.processes or None,
+            initializer=InitializerOrFinalizer(args.initializer),
+            finalizer=InitializerOrFinalizer(args.finalizer),
+        )
         manager = multiprocessing.Manager()
-        targets = [
-            (target, manager.Queue())
-            for target in toParallelTargets(suite, args.targets)
-        ]
+        targets = [(target, manager.Queue()) for target in parallel_targets]
         if targets:
-            pool = LoggingDaemonlessPool(
-                processes=args.processes or None,
-                initializer=InitializerOrFinalizer(args.initializer),
-                finalizer=InitializerOrFinalizer(args.finalizer),
-            )
             for index, (target, queue) in enumerate(targets):
                 if args.run_coverage:
                     coverage_number = index + 1
@@ -150,8 +150,8 @@ def run(suite, stream, args, testing=False):
                 if abort:
                     break
 
-            pool.close()
-            pool.join()
+        pool.close()
+        pool.join()
 
         result.stopTestRun()