Internal error when using `conflicts_with` with `ArgGroup` #3197

elomatreb · 2021-12-17T16:38:24Z

Please complete the following tasks

I have searched the discussions
I have searched the existing issues

Rust Version

rustc 1.57.0 (f1edd0429 2021-11-29)

Clap Version

3.0.0-rc.7

Minimal reproducible code

use clap::{App, Arg, ArgGroup};

fn main() {
    let m = App::new("demoapp")
        .arg(Arg::new("foo").long("foo").conflicts_with("argument-group"))
        .arg(Arg::new("bar").long("bar"))
        .group(ArgGroup::new("argument-group").arg("bar"))
        .get_matches();

    dbg!(m);
}

Steps to reproduce the bug with the above code

cargo run -- --foo

Actual Behaviour

The program panics, with the following internal error:

thread 'main' panicked at 'Fatal internal error. Please consider filing a bug report at https://github.com/clap-rs/clap/issues', /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/parse/validator.rs:240:18
stack backtrace:
   0: rust_begin_unwind
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/std/src/panicking.rs:517:5
   1: core::panicking::panic_fmt
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/panicking.rs:100:14
   2: core::panicking::panic_display
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/panicking.rs:64:5
   3: core::option::expect_failed
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/option.rs:1638:5
   4: core::option::Option<T>::expect
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/option.rs:709:21
   5: clap::parse::validator::Validator::build_conflict_err
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/parse/validator.rs:237:25
   6: clap::parse::validator::Validator::validate_conflicts::{{closure}}
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/parse/validator.rs:304:33
   7: core::iter::traits::iterator::Iterator::try_for_each::call::{{closure}}
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/traits/iterator.rs:2053:26
   8: core::iter::adapters::filter::filter_try_fold::{{closure}}
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/adapters/filter.rs:44:44
   9: core::iter::adapters::map::map_try_fold::{{closure}}
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/adapters/map.rs:91:21
  10: core::iter::traits::iterator::Iterator::try_fold
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/traits/iterator.rs:1995:21
  11: <core::iter::adapters::map::Map<I,F> as core::iter::traits::iterator::Iterator>::try_fold
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/adapters/map.rs:117:9
  12: <core::iter::adapters::filter::Filter<I,P> as core::iter::traits::iterator::Iterator>::try_fold
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/adapters/filter.rs:93:9
  13: core::iter::traits::iterator::Iterator::try_for_each
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/iter/traits/iterator.rs:2056:9
  14: clap::parse::validator::Validator::validate_conflicts
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/parse/validator.rs:264:9
  15: clap::parse::validator::Validator::validate
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/parse/validator.rs:72:9
  16: clap::parse::parser::Parser::get_matches_with
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/parse/parser.rs:702:9
  17: clap::build::app::App::_do_parse
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/build/app/mod.rs:2565:29
  18: clap::build::app::App::try_get_matches_from_mut
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/build/app/mod.rs:649:9
  19: clap::build::app::App::get_matches_from
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/build/app/mod.rs:519:9
  20: clap::build::app::App::get_matches
             at /home/elomatreb/.cargo/registry/src/github.com-1ecc6299db9ec823/clap-3.0.0-rc.7/src/build/app/mod.rs:431:9
  21: claptest::main
             at ./src/main.rs:4:13
  22: core::ops::function::FnOnce::call_once
             at /rustc/f1edd0429582dd29cccacaf50fd134b05593bd9c/library/core/src/ops/function.rs:227:5

Expected Behaviour

The program should work, outputting something like

[src/main.rs:10] m = ArgMatches {
    valid_args: [
        help,
        foo,
        bar,
        argument-group,
    ],
    valid_subcommands: [],
    args: {
        foo: MatchedArg {
            occurs: 1,
            ty: CommandLine,
            indices: [
                1,
            ],
            vals: [],
            ignore_case: false,
            invalid_utf8_allowed: Some(
                false,
            ),
        },
    },
    subcommand: None,
}

Additional Context

I am trying to make a single argument conflict with a ArgGroup (to save on repetition). If I instead place the conflicts_with("foo") on the argument group definition, it works as expected.

I'm assuming using the conflicts_with method on the individual argument should be possible too, but if it isn't supposed to be possible, a better error message would be good.

Debug Output

[            clap::build::app] 	App::_do_parse
[            clap::build::app] 	App::_build
[            clap::build::app] 	App::_propagate:demoapp
[            clap::build::app] 	App::_check_help_and_version
[            clap::build::app] 	App::_check_help_and_version: Removing generated version
[            clap::build::app] 	App::_propagate_global_args:demoapp
[            clap::build::app] 	App::_derive_display_order:demoapp
[clap::build::app::debug_asserts] 	App::_debug_asserts
[clap::build::arg::debug_asserts] 	Arg::_debug_asserts:help
[clap::build::arg::debug_asserts] 	Arg::_debug_asserts:foo
[clap::build::arg::debug_asserts] 	Arg::_debug_asserts:bar
[         clap::parse::parser] 	Parser::get_matches_with
[         clap::parse::parser] 	Parser::_build
[         clap::parse::parser] 	Parser::_verify_positionals
[         clap::parse::parser] 	Parser::get_matches_with: Begin parsing 'RawOsStr("--foo")' ([45, 45, 102, 111, 111])
[         clap::parse::parser] 	Parser::get_matches_with: Positional counter...1
[         clap::parse::parser] 	Parser::get_matches_with: Low index multiples...false
[         clap::parse::parser] 	Parser::possible_subcommand: arg=RawOsStr("--foo")
[         clap::parse::parser] 	Parser::get_matches_with: sc=None
[         clap::parse::parser] 	Parser::parse_long_arg
[         clap::parse::parser] 	Parser::parse_long_arg: cur_idx:=1
[         clap::parse::parser] 	Parser::parse_long_arg: Does it contain '='...
[         clap::parse::parser] 	No
[         clap::parse::parser] 	Parser::parse_long_arg: Found valid opt or flag '--foo'
[         clap::parse::parser] 	Parser::check_for_help_and_version_str
[         clap::parse::parser] 	Parser::check_for_help_and_version_str: Checking if --RawOsStr("foo") is help or version...
[         clap::parse::parser] 	Neither
[         clap::parse::parser] 	Parser::parse_long_arg: Presence validated
[         clap::parse::parser] 	Parser::parse_flag
[    clap::parse::arg_matcher] 	ArgMatcher::inc_occurrence_of_arg: id=foo
[            clap::build::app] 	App::groups_for_arg: id=foo
[         clap::parse::parser] 	Parser::get_matches_with: After parse_long_arg ValuesDone
[         clap::parse::parser] 	Parser::remove_overrides
[         clap::parse::parser] 	Parser::remove_overrides:iter:foo
[      clap::parse::validator] 	Validator::validate
[         clap::parse::parser] 	Parser::add_defaults
[      clap::parse::validator] 	Validator::validate_conflicts
[      clap::parse::validator] 	Validator::validate_exclusive
[      clap::parse::validator] 	Validator::validate_exclusive:iter:foo
[      clap::parse::validator] 	Validator::gather_conflicts
[      clap::parse::validator] 	Validator::gather_conflicts:iter: id=foo
[            clap::build::app] 	App::groups_for_arg: id=foo
[      clap::parse::validator] 	Validator::validate_conflicts:iter:argument-group
[            clap::build::app] 	App::unroll_args_in_group: group=argument-group
[            clap::build::app] 	App::unroll_args_in_group:iter: entity=bar
[            clap::build::app] 	App::unroll_args_in_group:iter: this is an arg
[      clap::parse::validator] 	Validator::build_conflict_err: name=argument-group
[         clap::output::usage] 	Usage::create_usage_with_title
[         clap::output::usage] 	Usage::create_usage_no_title
[         clap::output::usage] 	Usage::create_help_usage; incl_reqs=true
[         clap::output::usage] 	Usage::get_required_usage_from: incls=[], matcher=false, incl_last=false
[         clap::output::usage] 	Usage::get_required_usage_from: unrolled_reqs={}
[         clap::output::usage] 	Usage::get_required_usage_from: ret_val=[]
[         clap::output::usage] 	Usage::needs_options_tag
[         clap::output::usage] 	Usage::needs_options_tag:iter: f=help
[         clap::output::usage] 	Usage::needs_options_tag:iter Option is built-in
[         clap::output::usage] 	Usage::needs_options_tag:iter: f=foo
[            clap::build::app] 	App::groups_for_arg: id=foo
[         clap::output::usage] 	Usage::needs_options_tag:iter: [OPTIONS] required
[         clap::output::usage] 	Usage::create_help_usage: usage=claptest [OPTIONS]
[            clap::build::app] 	App::unroll_args_in_group: group=argument-group
[            clap::build::app] 	App::unroll_args_in_group:iter: entity=bar
[            clap::build::app] 	App::unroll_args_in_group:iter: this is an arg

The text was updated successfully, but these errors were encountered:

epage · 2021-12-17T17:02:04Z

Backported this to clap2 and it works

use clap::{App, Arg, ArgGroup};

fn main() {
    let m = App::new("demoapp")
        .arg(
            Arg::with_name("foo")
                .long("foo")
                .conflicts_with("argument-group"),
        )
        .arg(Arg::with_name("bar").long("bar"))
        .group(ArgGroup::with_name("argument-group").arg("bar"))
        .get_matches();

    dbg!(m);
}

Its interesting the panic in clap3 happens with cargo run -- --foo but not --bar, --foo --bar, or --help.

Debug output:

DEBUG:clap:Validator::validate;
DEBUG:clap:Parser::add_defaults;
DEBUG:clap:Validator::validate_blacklist;
DEBUG:clap:Validator::validate_blacklist:iter:foo;
DEBUG:clap:Parser::groups_for_arg: name=foo
DEBUG:clap:Parser::groups_for_arg: Searching through groups...
DEBUG:clap:Validator::validate_required: required=[];
DEBUG:clap:Validator::validate_matched_args;
DEBUG:clap:Validator::validate_matched_args:iter:foo: vals=[]
DEBUG:clap:Validator::validate_arg_requires:foo;
DEBUG:clap:Validator::validate_arg_num_occurs: a=foo;
DEBUG:clap:usage::create_usage_with_title;
DEBUG:clap:usage::create_usage_no_title;
DEBUG:clap:usage::get_required_usage_from: reqs=[], extra=None
DEBUG:clap:usage::get_required_usage_from: after init desc_reqs=[]
DEBUG:clap:usage::get_required_usage_from: no more children
DEBUG:clap:usage::get_required_usage_from: final desc_reqs=[]
DEBUG:clap:usage::get_required_usage_from: args_in_groups=[]
DEBUG:clap:usage::needs_flags_tag;
DEBUG:clap:usage::needs_flags_tag:iter: f=foo;
DEBUG:clap:Parser::groups_for_arg: name=foo
DEBUG:clap:Parser::groups_for_arg: Searching through groups...
DEBUG:clap:usage::needs_flags_tag:iter: [FLAGS] required
DEBUG:clap:usage::create_help_usage: usage=test-clap [FLAGS]
DEBUG:clap:ArgMatcher::get_global_values: global_arg_vec=[]
[src/main.rs:14] m = ArgMatches {
    args: {
        "foo": MatchedArg {
            occurs: 1,
            indices: [
                1,
            ],
            vals: [],
        },
    },
    subcommand: None,
    usage: Some(
        "USAGE:\n    test-clap [FLAGS]",
    ),
}

epage · 2021-12-21T21:51:08Z

We handle conflicts in two phases

gather potential conflicts: we unconditionally add argument-group when --foo is present
check conflicts: with --foo present and argument-group previously added, these conflict (arg_conf_with_gr)

There is some deleted code in gather_conflicts so I wondered if #2512 is what caused this but I went to 6e158d9~ and it still paniced.

Found this when digging into clap-rs#3197

We are looping over the arguments set by the parser. In one case, we are checking to see if the argument is a group. I am not seeing us set groups in the matcher when parsing and we have a debug assert ensuring arg and group names don't conflict. This looks like dead code to me. I am hesitant making a change like this right before release but this is part of trying to make the code understandable for root causing and fixing clap-rs#3197

Found this when digging into clap-rs#3197

We are looping over the arguments set by the parser. In one case, we are checking to see if the argument is a group. I am not seeing us set groups in the matcher when parsing and we have a debug assert ensuring arg and group names don't conflict. This looks like dead code to me. I am hesitant making a change like this right before release but this is part of trying to make the code understandable for root causing and fixing clap-rs#3197

epage · 2021-12-22T17:33:13Z

The crux of the issue is how we communicate between the two phases (gather, check): we gather groups for both present args and that conflict with present args. These become contradictory.

What I'm trying to understand next is why the algorithm shifted so much from clap v2

epage · 2021-12-22T17:58:29Z

7673dfc appears to be the first major change though at a glance it seems like its keeping the basic operations, just changing the code to show errors prioritized by argument index.

5a06a82 is what seems to fundamentally change things to address #1158.

Fixes clap-rs#3197

epage · 2021-12-23T20:30:10Z

3.0.0-rc.8 is released with the fix for this

elomatreb added the C-bug Category: Updating dependencies label Dec 17, 2021

epage added this to the 3.0 milestone Dec 17, 2021

epage added A-validators Area: ArgMatches validation logi E-medium Call for participation: Experience needed to fix: Medium / intermediate labels Dec 17, 2021

epage mentioned this issue Dec 21, 2021

refactor(validator): cleanup code #2512

Merged

epage added a commit to epage/clap that referenced this issue Dec 22, 2021

fix: Ensure we validate required-unless

9e700d1

Found this when digging into clap-rs#3197

epage mentioned this issue Dec 22, 2021

fix: Ensure we validate required-unless #3205

Merged

epage mentioned this issue Dec 22, 2021

refactor: Remove dead code #3206

Closed

epage added a commit to epage/clap that referenced this issue Dec 22, 2021

fix: Ensure we validate required-unless

2e73be4

Found this when digging into clap-rs#3197

epage added a commit to epage/clap that referenced this issue Dec 23, 2021

WIP: fix: Don't panic on lack of conflicts

5b54b08

Fixes clap-rs#3197

epage added a commit to epage/clap that referenced this issue Dec 23, 2021

fix: Don't panic on lack of conflicts

1b41ecb

Fixes clap-rs#3197

epage mentioned this issue Dec 23, 2021

fix: Don't panic on lack of conflicts #3212

Merged

epage added a commit to epage/clap that referenced this issue Dec 23, 2021

fix: Don't panic on lack of conflicts

3db09f4

Fixes clap-rs#3197

epage closed this as completed in #3212 Dec 23, 2021

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Internal error when using `conflicts_with` with `ArgGroup` #3197

Internal error when using `conflicts_with` with `ArgGroup` #3197

elomatreb commented Dec 17, 2021

epage commented Dec 17, 2021 •

edited

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epage commented Dec 21, 2021

epage commented Dec 22, 2021

epage commented Dec 22, 2021

epage commented Dec 23, 2021

Internal error when using conflicts_with with ArgGroup #3197

Internal error when using conflicts_with with ArgGroup #3197

Comments

elomatreb commented Dec 17, 2021

Please complete the following tasks

Rust Version

Clap Version

Minimal reproducible code

Steps to reproduce the bug with the above code

Actual Behaviour

Expected Behaviour

Additional Context

Debug Output

epage commented Dec 17, 2021 • edited Loading

epage commented Dec 21, 2021

epage commented Dec 22, 2021

epage commented Dec 22, 2021

epage commented Dec 23, 2021

Internal error when using `conflicts_with` with `ArgGroup` #3197

Internal error when using `conflicts_with` with `ArgGroup` #3197

epage commented Dec 17, 2021 •

edited

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