x.py has exponental resource usage with no progress

[Kixiron]

I attempted to use x.py with all of the following commands

$ python x.py --help
$ python x.py build -j1 --stage 1 src/libstd
$ python x.py build -i -j1 --stage 1 src/libstd
$ python x.py build -i --stage 1 src/libstd

but instead of doing what it's supposed to do, there was instead zero terminal output and and continuously increasing number of spawned python processes, ranging from 3827 pythons with x.py --help to well over 10000 pythons with python x.py build -j1 --stage 1 src/libstd. This number was steadily increasing though, I just had to kill it before my computer crashed. Killing the builds was also incredibly difficult, ctrl+cs do nothing, task manager crashes when it's opened and x'ing the window does nothing. The only semi-reliable way I found to kill the process was to kill every python process that was running, then x.py exited with still no output. On the python x.py build -i --stage 1 src/libstd command in particular, the spawning was so out of control that I had to restart my entire system in order to regain control.

This was the first build of rustc that I've done, so there were no prior or cached artifacts

Meta

Arch

Windows 10 Pro version 1909, OS build 18363.836
Python 3.7.3
The results were the same in both Powershell and CMD

Git

This occurred on 4774f9b, but I haven't attempted to bisect for the root cause yet

config.toml

These were the only configuration values that I changed

[llvm]
assertions = true

[build]
verbose = 1
profiler = true

[rust]
debug = true
codegen-units = 0
debug-assertions = true
backtrace = true
parallel-compiler = true

[Kixiron]

I believe I've found part of the problem, the shebang was doing something really weird and hiding all output. Changing the shebang in x.py to #! /usr/bin/python fixed the no-output problem perfectly

[Kixiron]

This may be partially due to the fact that on my system I have python as an alias to python3, while both py and python3 both do nothing

[ratijas]

both py and python3 both do nothing

What do you mean?

[mati865]

Changing the shebang in x.py to #! /usr/bin/python fixed the no-output problem perfectly

That would break building inside MSYS2 (and maybe Git for Windows) shell.

This may be partially due to the fact that on my system I have python as an alias to python3,

Maybe it doesn't like the alias?

while both py and python3 both do nothing

What do you mean? Runinng python3 x.py does nothing?

[Kixiron]

python3 and py are unbound on my system

[Kixiron]

After a little investigation, it seems that #! /usr/bin/env python is infinitely recursing!

[ratijas]

After a little investigation, it seems that #! /usr/bin/env python is infinitely recursing!

So, ultimately, it's a problem with your setup, and not in x.py or rust itself?

[Kixiron]

I guess so, closing for that reason