Improve error messages for early Bazel failures
Tulsi previously only used stdout/stderr from Bazel's BEP during builds
inside of the IDE. This is of course problematic for Bazel failures
which occur before BEP can be initialized.
As a workaround, if we are unable to read any build events via BEP, we
output Bazel's stdout/stderr directly.
This change also makes the error messages a bit more useful by pointing
Xcode to the bazel_build.py script, so the user has more insight into
errors generated by our script.
PiperOrigin-RevId: 209837296
diff --git a/src/TulsiGenerator/Scripts/bazel_build.py b/src/TulsiGenerator/Scripts/bazel_build.py
index 4d96661..11990a6 100755
--- a/src/TulsiGenerator/Scripts/bazel_build.py
+++ b/src/TulsiGenerator/Scripts/bazel_build.py
@@ -1,4 +1,5 @@
#!/usr/bin/python
+# -*- coding: utf-8 -*-
# Copyright 2016 The Tulsi Authors. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
@@ -18,6 +19,7 @@
import atexit
import errno
import fcntl
+import inspect
import io
import json
import os
@@ -53,6 +55,11 @@
_logger = None
+def _PrintUnbuffered(msg):
+ sys.stdout.write('%s\n' % msg)
+ sys.stdout.flush()
+
+
def _PrintXcodeWarning(msg):
sys.stdout.write(':: warning: %s\n' % msg)
sys.stdout.flush()
@@ -63,6 +70,15 @@
sys.stderr.flush()
+def _Fatal(msg, fatal_frame=None):
+ """Print a fatal error pointing to the failure line inside the script."""
+ if not fatal_frame:
+ fatal_frame = inspect.currentframe().f_back
+ filename, line_number, _, _, _ = inspect.getframeinfo(fatal_frame)
+ _PrintUnbuffered('%s:%d: error: %s' % (os.path.abspath(filename),
+ line_number, msg))
+
+
CLEANUP_BEP_FILE_AT_EXIT = False
@@ -82,7 +98,7 @@
def _InterruptHandler(signum, frame):
"""Gracefully exit on SIGINT."""
del signum, frame # Unused.
- sys.stdout.write('Caught interrupt signal. Exiting...\n')
+ _PrintUnbuffered('Caught interrupt signal. Exiting...')
sys.exit(0)
@@ -134,8 +150,7 @@
lock_path: Path to the lock file.
"""
# TODO(b/74119354): Add lockfile timer back and lazily instantiate logger.
- sys.stdout.write('Queuing Tulsi build...\n')
- sys.stdout.flush()
+ _PrintUnbuffered('Queuing Tulsi build...')
# TODO(b/69414272): See if we can improve this for multiple WORKSPACEs.
lockfile = open(lock_path, 'w')
# Register "fclose(...)" as early as possible, before acquiring lock.
@@ -280,9 +295,8 @@
return bazel, start_up, all_build
def _WarnUnknownPlatform(self):
- sys.stdout.write('Warning: unknown platform "%s" will be treated as '
- 'iOS\n' % self.platform_name)
- sys.stdout.flush()
+ _PrintUnbuffered('Warning: unknown platform "%s" will be treated as '
+ 'iOS' % self.platform_name)
def _ParseVariableOptions(self, args):
"""Parses flag-based args, returning (message, exit_code)."""
@@ -317,9 +331,8 @@
reported_version = os.environ['XCODE_VERSION_ACTUAL']
match = re.match(r'(\d{2})(\d)(\d)$', reported_version)
if not match:
- sys.stdout.write('Warning: Failed to extract Xcode version from %s\n' % (
+ _PrintUnbuffered('Warning: Failed to extract Xcode version from %s' % (
reported_version))
- sys.stdout.flush()
return None
major_version = int(match.group(1))
minor_version = int(match.group(2))
@@ -512,16 +525,18 @@
exit_code, outputs = self._RunBazelAndPatchOutput(command)
timer.End()
if exit_code:
- _PrintXcodeError('Bazel build failed.')
+ _Fatal('Bazel build failed with exit code %d. Please check the build '
+ 'log in Report Navigator (⌘9) for more information.'
+ % exit_code)
return exit_code
post_bazel_timer = Timer('Total Tulsi Post-Bazel time', 'total_post_bazel')
post_bazel_timer.Start()
if not os.path.exists(self.bazel_exec_root):
- _PrintXcodeError('No Bazel execution root was found at %s. Debugging '
- 'experience will be compromised. Please report a Tulsi '
- 'bug.' % self.bazel_exec_root)
+ _Fatal('No Bazel execution root was found at %r. Debugging experience '
+ 'will be compromised. Please report a Tulsi bug.'
+ % self.bazel_exec_root)
return 404
# This needs to run after `bazel build`, since it depends on the Bazel
@@ -699,22 +714,33 @@
new_outputs.extend(outputs)
return new_outputs
+ def ReaderThread(file_handle, out_buffer):
+ out_buffer.append(file_handle.read())
+ file_handle.close()
+
# Make sure the BEP JSON file exists and is empty. We do this to prevent
# any sort of race between the watcher, bazel, and the old file contents.
open(self.build_events_file_path, 'w').close()
- # Start Bazel without any extra files open besides /dev/null, which is
- # used to ignore the output.
- with open(os.devnull, 'w') as devnull:
- process = subprocess.Popen(command,
- stdout=devnull,
- stderr=subprocess.STDOUT)
+ # Capture the stderr and stdout from Bazel. We only display it if it we're
+ # unable to read any BEP events.
+ process = subprocess.Popen(command,
+ stdout=subprocess.PIPE,
+ stderr=subprocess.STDOUT,
+ bufsize=1)
# Register atexit function to clean up BEP file.
atexit.register(_BEPFileExitCleanup, self.build_events_file_path)
global CLEANUP_BEP_FILE_AT_EXIT
CLEANUP_BEP_FILE_AT_EXIT = True
+ # Start capturing output from Bazel.
+ reader_buffer = []
+ reader_thread = threading.Thread(target=ReaderThread,
+ args=(process.stdout, reader_buffer))
+ reader_thread.daemon = True
+ reader_thread.start()
+
with io.open(self.build_events_file_path, 'r', -1, 'utf-8', 'ignore'
) as bep_file:
watcher = bazel_build_events.BazelBuildEventsWatcher(bep_file,
@@ -727,6 +753,12 @@
output_locations.extend(WatcherUpdate(watcher))
+ # If BEP JSON parsing failed, we should display the raw stdout and
+ # stderr from Bazel.
+ reader_thread.join()
+ if not watcher.has_read_events():
+ HandleOutput(reader_buffer[0])
+
if process.returncode == 0 and not output_locations:
CLEANUP_BEP_FILE_AT_EXIT = False
_PrintXcodeError('Unable to find location of the .tulsiouts file.'
@@ -1626,15 +1658,13 @@
def _PrintVerbose(self, msg, level=0):
if self.verbose > level:
- sys.stdout.write(msg + '\n')
- sys.stdout.flush()
+ _PrintUnbuffered(msg)
def main(argv):
build_settings = bazel_build_settings.BUILD_SETTINGS
if build_settings is None:
- _PrintXcodeError('Unable to resolve build settings. '
- 'Please report a Tulsi bug.')
+ _Fatal('Unable to resolve build settings. Please report a Tulsi bug.')
return 1
return BazelBuildBridge(build_settings).Run(argv)
diff --git a/src/TulsiGenerator/Scripts/bazel_build_events.py b/src/TulsiGenerator/Scripts/bazel_build_events.py
index 53722b5..cc6e3c5 100755
--- a/src/TulsiGenerator/Scripts/bazel_build_events.py
+++ b/src/TulsiGenerator/Scripts/bazel_build_events.py
@@ -106,6 +106,10 @@
"""
self.file_reader = _FileLineReader(json_file)
self.warning_handler = warning_handler
+ self._read_any_events = False
+
+ def has_read_events(self):
+ return self._read_any_events
def check_for_new_events(self):
"""Checks the file for new BazelBuildEvents.
@@ -126,6 +130,7 @@
handler('Could not decode BEP event "%s"\n' % line)
handler('Received error of %s, "%s"\n' % (type(e), e))
break
+ self._read_any_events = True
build_event = BazelBuildEvent(build_event_dict)
new_events.append(build_event)
return new_events
