keep a heap dump when the leak test fails

Author: timfel

mx.graalpython/mx_graalpython.py

@@ -1991,8 +1991,10 @@ def import_files(from_dir, to_dir):
     SUITE.vc.git_command(SUITE.dir, ["merge", HPY_IMPORT_ORPHAN_BRANCH_NAME])
 
 
-def run_leak_launcher(args):
-    print("Leak test: " + " ".join(args))
+def run_leak_launcher(input_args, out=None):
+    print("mx python-leak-test " + " ".join(input_args))
+
+    args = input_args
     capi_home = _get_capi_home()
     args.insert(0, "--experimental-options")
     args.insert(0, "--python.CAPI=%s" % capi_home)
@@ -2006,10 +2008,24 @@ def run_leak_launcher(args):
     vm_args += mx.get_runtime_jvm_args(dists)
     jdk = mx.get_jdk(tag=None)
     vm_args.append("com.oracle.graal.python.test.advance.LeakTest")
-    retval = mx.run_java(vm_args + graalpython_args, jdk=jdk, env=env, nonZeroIsFatal=False)
+    retval = mx.run_java(vm_args + graalpython_args, jdk=jdk, env=env, nonZeroIsFatal=False, out=out)
     if retval == 0:
         print("PASSED")
         return True
+    elif os.environ.get("CI") and "--keep-dump" not in input_args:
+        # rerun once with heap dumping enabled
+        out = mx.OutputCapture()
+        run_leak_launcher(["--keep-dump"] + input_args, out=out)
+        path = out.data.strip().split("Dump file:")[2].strip()
+        if path:
+            save_path = os.path.join(SUITE.dir, "dumps", "leak_test")
+            try:
+                os.makedirs(save_path)
+            except OSError:
+                pass
+            dest = shutil.copy(path, save_path)
+            print("Heapdump file kept in " + dest)
+        return False
     else:
         print("FAILED")
         return False