I found that this breaks on CentOS because it doesn't have which available. I'll use command -v instead.

This breaks in Powershell (probably cmd.exe too, but I don't know how to install that on linux):

ResourceUnavailable: Program 'x.py' failed to run: Exec format errorAt line:1 char:1
+ ./x.py check
+ ~~~~~~~~~~~~.

It looks like servo handles this by having a separate mach.bat bootstrap script, which seems unfortunate :/

Are you sure this isn't missing a shebang for shell of some sort?

Running ./x.py on a NixOS system with this PR does not work:

$ git checkout origin/master
$ ./x.py
info: Downloading and building bootstrap before processing --help
      command. See src/bootstrap/README.md for help with common
      commands.
Updating only changed submodules
Updating submodule src/llvm-project
<snip>
$ git checkout origin/pr/80585
$ ./x.py
Failed to execute process './x.py'. Reason:
exec: unknown error (errno was 8)
The file './x.py' is marked as an executable but could not be run by the operating system.

@nagisa most shells will execute files as scripts if they don't have a shebang, what shell are you using?

That said, if this doesn't work even on linux, it's probably not worth pursuing.

I use fish and various non-shell uses would probably break as well.