My alias-expanding sudo hangs with 0.8.1

[t184256]

In xonsh 0.8.1 with --no-rc I can do sudo ls | less and it works fine.

With a .xonshrc consisting of the following lines only:

# make sudo expand aliases
def sudo_expanding_aliases(args, stdin=None):
    /usr/bin/env sudo @(aliases.eval_alias(args))
aliases['sudo'] = sudo_expanding_aliases
del sudo_expanding_aliases

/usr/bin/env sudo ls | less works as expected, while sudo ls | less hangs hard since 0.8.1, C-C or C-\ do not help.

Couldn't find any relevant recent changes at the first glance, were there any?

[scopatz]

Thanks for reporting @t184256! Actually, on 0.8.0, I am getting sudo ls | less hanging with that alias, so I don't think that 0.8.1 broke it in any real way.

I think that the main issue here is that stdout in the alias isn't be redirected correctly.

[scopatz]

I think this is the right way to write such an alias:

def sudo_expanding_aliases(args, stdin=None, stdout=None): 
    p = !(/usr/bin/env sudo @(aliases.eval_alias(args))) 
    for line in p: 
         stdout.write(line) 
    return p.returncode

aliases['sudo'] = sudo_expanding_aliases 
del sudo_expanding_aliases 

[scopatz]

We should probably have sudo, env and a few others always expand aliases too, though.

[t184256]

I've tried your suggestion way and it doesn't play nice with interactive commands like vi. Went back to #2618 (comment)

[scopatz]

Let us know if there is anything specific we can do

[t184256]

I am very sorry, I don't know how to put it into a specific request. Honestly, I want sudo to expand aliases in a way that "Just Works" (tm).

Currently my version hangs hard on my example, while your version hangs on any interactive command, alias or not, displaying a lone ^Z.

Is anything I can do to provide more info on this? Could you fix my version? What do others use?

[scopatz]

Yeah, I am honstely pretty confused about what is going on here

[t184256]

Does 0.8.10 alias work bring anything new to the table?

[scopatz]

It probably does, but I haven't had a chance to look at this issue specifically.

[anki-code]

I've taken a short look into this.

1. At this time the alias resolving is working only for the first argument. And in xonsh the command bash ls (where ls is alias ls --color) is working like in bash (without resolving) i.e bash ls is bash ls instead of bash ls --color.

2. I've also tried ExecAlias to solve this but without success (with feat: Added ability to get arguments list in ExecAlias #4201 and feat: Ability to call the program by name from callable alias with the same name without the infinite loop error #4218):

aliases['sudo'] = 'sudo @(aliases.eval_alias($args))'    # ExecAlias
sudo ls | less
# no response

3. The start point to research is here.

UPD: this is my old try to solve this and it's mostly outdated but I leave it here for education of a stranger who digging here.

I tried to solve this issue by manipulating with predictors.

This alias is working with piping into capturable tools like grep:

from xonsh.commands_cache import predict_false, predict_true

def sudo_expanding_aliases(cmd, stdin=None, stdout=None, stderr=None):
    curr_sudo_predictor = __xonsh__.commands_cache.threadable_predictors['sudo']
    try:
        __xonsh__.commands_cache.threadable_predictors['sudo'] = predict_true
        if r := ![sudo echo -n]:  # to get password prompt in uncapturable mode
            if __xonsh__.commands_cache.predict_threadable(cmd):
                __xonsh__.commands_cache.threadable_predictors['sudo'] = predict_true
                p = !(sudo @(aliases.eval_alias(cmd)))
                p.end()
                for line in p:
                    stdout.write(line)
                if p.errors:
                    for line in p.errors.splitlines():
                        stderr.write(line + '\n')
                __xonsh__.commands_cache.threadable_predictors['sudo'] = curr_sudo_predictor
                return p.returncode
            else:
                __xonsh__.commands_cache.threadable_predictors['sudo'] = predict_false
                r = ![sudo @(aliases.eval_alias(cmd))]
                __xonsh__.commands_cache.threadable_predictors['sudo'] = curr_sudo_predictor
                return r.rtn
    finally:
        __xonsh__.commands_cache.threadable_predictors['sudo'] = curr_sudo_predictor

aliases['sudo'] = sudo_expanding_aliases
del sudo_expanding_aliases

sudo ls / | grep bin
# bin
# sbin

But this alias is not working with uncapturable tools like less.

[anki-code]

I'm going to close this as duplicate #2618