Error out in case of std errors in blackbox test and export file in TARGETS

Summary:
-  Right now in blackbox test we don't exit if there are std::error as we do in whitebox crash tests. As result those errors are swallowed.
It only errors out if state is unexpected.

One example that was noticed in blackbox crash test -
```
stderr has error message:
***Error restoring historical expected values: Corruption: DB is older than any restorable expected state***
Running db_stress with pid=30454: /packages/rocksdb_db_stress_internal_repo/rocks_db_stress  ....
```

-  This diff also provided support to export files -  db_crashtest.py file to be used by different repo.

Reviewed By: ajkr

Differential Revision: D50564889

fbshipit-source-id: 7bafbbc6179dc79467ca2b680fe83afc7850616a

TARGETS

@@ -5620,3 +5620,5 @@ cpp_unittest_wrapper(name="write_unprepared_transaction_test",
             deps=[":rocksdb_test_lib"],
             extra_compiler_flags=[])
 
+
+export_file(name = "tools/db_crashtest.py")

buckifier/buckify_rocksdb.py

@@ -303,6 +303,7 @@ def generate_targets(repo_path, deps_map):
                     deps=json.dumps(deps["extra_deps"] + [":rocksdb_test_lib"]),
                     extra_compiler_flags=json.dumps(deps["extra_compiler_flags"]),
                 )
+    TARGETS.export_file("tools/db_crashtest.py")
 
     print(ColorString.info("Generated TARGETS Summary:"))
     print(ColorString.info("- %d libs" % TARGETS.total_lib))

buckifier/targets_builder.py

@@ -148,3 +148,9 @@ add_c_test_wrapper()
                 ).encode("utf-8")
             )
         self.total_test = self.total_test + 1
+
+    def export_file(self, name):
+        with open(self.path, "a") as targets_file:
+            targets_file.write(
+                targets_cfg.export_file_template.format(name=name)
+            )

buckifier/targets_cfg.py

@@ -37,3 +37,7 @@ fancy_bench_template = """
 fancy_bench_wrapper(suite_name="{name}", binary_to_bench_to_metric_list_map={bench_config}, slow={slow}, expected_runtime={expected_runtime}, sl_iterations={sl_iterations}, regression_threshold={regression_threshold})
 
 """
+
+export_file_template = """
+export_file(name = "{name}")
+"""

tools/db_crashtest.py

@@ -846,6 +846,17 @@ def blackbox_crash_main(args, unknown_args):
                 print("stderr has error message:")
                 print("***" + line + "***")
 
+        stderrdata = errs.lower()
+        errorcount = stderrdata.count("error") - stderrdata.count("got errors 0 times")
+        print("#times error occurred in output is " + str(errorcount) + "\n")
+
+        if errorcount > 0:
+            print("TEST FAILED. Output has 'error'!!!\n")
+            sys.exit(2)
+        if stderrdata.find("fail") >= 0:
+            print("TEST FAILED. Output has 'fail'!!!\n")
+            sys.exit(2)
+
         time.sleep(1)  # time to stabilize before the next run
 
         time.sleep(1)  # time to stabilize before the next run
@@ -869,6 +880,17 @@ def blackbox_crash_main(args, unknown_args):
             print("stderr has error message:")
             print("***" + line + "***")
 
+    stderrdata = errs.lower()
+    errorcount = stderrdata.count("error") - stderrdata.count("got errors 0 times")
+    print("#times error occurred in output is " + str(errorcount) + "\n")
+
+    if errorcount > 0:
+        print("TEST FAILED. Output has 'error'!!!\n")
+        sys.exit(2)
+    if stderrdata.find("fail") >= 0:
+        print("TEST FAILED. Output has 'fail'!!!\n")
+        sys.exit(2)
+
     # we need to clean up after ourselves -- only do this on test success
     shutil.rmtree(dbname, True)