Piping to ppl does not return on Mac

[amitkot]

Trying pipeliner on a Mac and the command never returns.

This does not return:

> echo 1 | ppl 'line'

Neither does this:

> echo 1 | ppl 'line' | cat

> xonfig
+------------------+----------------------+
| xonsh            | 0.10.1               |
| Git SHA          | 337cf25a             |
| Commit Date      | Nov 17 15:37:41 2021 |
| Python           | 3.9.9                |
| PLY              | 3.11                 |
| have readline    | True                 |
| prompt toolkit   | 3.0.24               |
| shell type       | prompt_toolkit       |
| history backend  | json                 |
| pygments         | 2.11.2               |
| on posix         | True                 |
| on linux         | False                |
| on darwin        | True                 |
| on windows       | False                |
| on cygwin        | False                |
| on msys2         | False                |
| is superuser     | False                |
| default encoding | utf-8                |
| xonsh encoding   | utf-8                |
| encoding errors  | surrogateescape      |
| on jupyter       | True                 |
| jupyter kernel   | None                 |
| xontrib 1        | bashisms             |
| xontrib 2        | coreutils            |
| xontrib 3        | jedi                 |
| xontrib 4        | pipeliner            |
| xontrib 5        | pyenv                |
| xontrib 6        | sh                   |
| xontrib 7        | vox                  |
| xontrib 8        | vox_tabcomplete      |
| xontrib 9        | voxapi               |
+------------------+----------------------+

[anki-code]

This looks like a known issue - https://github.com/anki-code/xontrib-pipeliner#ppl-on-macos-multicore-pipelining-freezes-on-end

[anki-code]

You can use pl instead of ppl on mac.

[amitkot]

Sadly these do not work as well:

> echo 1 | pl 'line'

> echo 1 | pl 'line' | cat

[amitkot]

@anki-code Is there a "debug" flag I can run with to see why it freezes?

[amitkot]

@anki-code I really like this idea, but this does not work for me. Any idea how to make it work?

[anki-code]

May be this is also related to $XONSH_CAPTURE_ALWAYS.
Try to set $XONSH_CAPTURE_ALWAYS = True before usage.

[anki-code]

@amitkot pl is a callable alias:

xontrib-pipeliner/xontrib/pipeliner/__init__.py

Lines 9 to 38 in 022071c

	def _pl(args, stdin, stdout):
	err = False
	if len(args) == 0:
	print('Error: Python code not found', file=sys.stderr)
	err = True
	if err:
	print('Usage: <command> | <command> | ... | pl "<Python code>"', file=sys.stderr)
	print('Example: echo "123" | pl "line[::-1]"', file=sys.stderr)
	return
	fn = eval('lambda line, num:'+args[0], __xonsh__.ctx)
	if stdin is None:
	try:
	print(fn(None, 0))
	except:
	print_color('{YELLOW}' + str(traceback.format_exc()), file=sys.stderr)
	return
	num = 0
	for line in stdin.readlines():
	try:
	res = fn(line.rstrip(os.linesep), num)
	except:
	print_color('{YELLOW}' + f'Error line {num+1}: {line}', file=sys.stderr)
	print_color('{YELLOW}' + str(traceback.format_exc()), file=sys.stderr)
	return
	num += 1
	if res is not None:
	print(res, file=stdout, flush=True)

So as a good start you can just debug this function on mac.