Bug/inconsistency with the help formatting

[golddranks]

Not sure if this is intended or not, but I can't see any reason for this: the value name of trailing var arguments is printed differently in the usage string from how it's printed in the argument list.

Rust Version

rustc 1.18.0-nightly (2bd4b5c6d 2017-04-23)

Affected Version of clap

clap 2.23.2

Expected Behavior Summary

$ cargo flamegraph --help

Should print out:

cargo-flamegraph

USAGE:
    cargo flamegraph [FLAGS] [OPTIONS] [<BINFILE>] [-- <ARGS>...]

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information
    -v, --verbose    Prints out more stuff.

OPTIONS:
    -f, --frequency <HERTZ>    The sampling frequency. By default, this is 99 Hz.
    -t, --timeout <SECONDS>    Timeout in seconds. By default, there is no timeout.

ARGS:
    <BINFILE>    The path of the binary to be profiled. If empty, Cargo.toml is searched for a binary.
    <ARGS>...       Any arguments you wish to pass to the binary being profiled.

Actual Behavior Summary

It prints out: (Note the discrepancy between <pass through args> and <ARGS>...)

cargo-flamegraph

USAGE:
    cargo flamegraph [FLAGS] [OPTIONS] [<BINFILE>] [-- <pass through args>]

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information
    -v, --verbose    Prints out more stuff.

OPTIONS:
    -f, --frequency <HERTZ>    The sampling frequency. By default, this is 99 Hz.
    -t, --timeout <SECONDS>    Timeout in seconds. By default, there is no timeout.

ARGS:
    <BINFILE>    The path of the binary to be profiled. If empty, Cargo.toml is searched for a binary.
    <ARGS>...       Any arguments you wish to pass to the binary being profiled.

Steps to Reproduce the issue

N/A

Sample Code or Link to Sample Code

fn main() {
    let matches = App::new("cargo flamegraph")
        .version("0.1")
        .bin_name("cargo")
        .about("Profiles your program and draws a nice flamegraph!")
        .author("Pyry Kontio")
        .setting(AppSettings::TrailingVarArg)
        .subcommand(SubCommand::with_name("flamegraph")
            .arg(Arg::with_name("verbose")
                .help("Prints out more stuff.")
                .short("v")
                .long("verbose")
                .multiple(true)
            )
            .arg(Arg::with_name("timeout")
                .help("Timeout in seconds. By default, there is no timeout.")
                .short("t")
                .long("timeout")
                .value_name("SECONDS")
                .takes_value(true)
            )
            .arg(Arg::with_name("frequency")
                .help("The sampling frequency. By default, this is 99 Hz.")
                .short("f")
                .long("frequency")
                .value_name("HERTZ")
                .takes_value(true)
            )
            .arg(Arg::with_name("binary path")
                .help("The path of the binary to be profiled. If empty, Cargo.toml is searched for a binary.")
                .takes_value(true)
                .value_name("BINFILE")
            )
            .arg(Arg::with_name("pass through args")
                .help("Any arguments you wish to pass to the binary being profiled.")
                .value_name("ARGS")
                .last(true)
                .multiple(true)
            )
        )
        .get_matches();
}

Debug output

DEBUG:clap:Parser::add_subcommand: term_w=None, name=flamegraph
DEBUG:clap:Parser::propogate_settings: self=cargo flamegraph, g_settings=AppFlags(
NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
)
DEBUG:clap:Parser::propogate_settings: sc=flamegraph, settings=AppFlags(
NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO | DONT_COLLAPSE_ARGS | CONTAINS_LAST
), g_settings=AppFlags(
NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
)
DEBUG:clap:Parser::propogate_settings: self=flamegraph, g_settings=AppFlags(
NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
)
DEBUG:clap:Parser::get_matches_with;
DEBUG:clap:Parser::create_help_and_version;
DEBUG:clap:Parser::create_help_and_version: Building --help
DEBUG:clap:Parser::create_help_and_version: Building --version
DEBUG:clap:Parser::create_help_and_version: Building help
DEBUG:clap:Parser::get_matches_with: Begin parsing '"flamegraph"' ([102, 108, 97, 109, 101, 103, 114, 97, 112, 104])
DEBUG:clap:Parser::is_new_arg: arg="flamegraph", Needs Val of=None
DEBUG:clap:Parser::is_new_arg: Arg::allow_leading_hyphen(false)
DEBUG:clap:Parser::is_new_arg: probably value
DEBUG:clap:Parser::is_new_arg: starts_new_arg=false
DEBUG:clap:Parser::possible_subcommand: arg="flamegraph"
DEBUG:clap:Parser::get_matches_with: possible_sc=true, sc=Some("flamegraph")
DEBUG:clap:Parser::parse_subcommand;
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:Parser::parse_subcommand: About to parse sc=flamegraph
DEBUG:clap:Parser::parse_subcommand: sc settings=AppFlags(
NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO | DONT_COLLAPSE_ARGS | CONTAINS_LAST
)
DEBUG:clap:Parser::get_matches_with;
DEBUG:clap:Parser::create_help_and_version;
DEBUG:clap:Parser::create_help_and_version: Building --help
DEBUG:clap:Parser::create_help_and_version: Building --version
DEBUG:clap:Parser::get_matches_with: Begin parsing '"--help"' ([45, 45, 104, 101, 108, 112])
DEBUG:clap:Parser::is_new_arg: arg="--help", Needs Val of=None
DEBUG:clap:Parser::is_new_arg: Arg::allow_leading_hyphen(false)
DEBUG:clap:Parser::is_new_arg: -- found
DEBUG:clap:Parser::is_new_arg: starts_new_arg=true
DEBUG:clap:Parser::possible_subcommand: arg="--help"
DEBUG:clap:Parser::get_matches_with: possible_sc=false, sc=None
DEBUG:clap:Parser::parse_long_arg;
DEBUG:clap:Parser::parse_long_arg: Does it contain '='...No
DEBUG:clap:Parser::parse_long_arg: Found valid flag '--help'
DEBUG:clap:Parser::check_for_help_and_version_str;
DEBUG:clap:Parser::check_for_help_and_version_str: Checking if --help is help or version...Help
DEBUG:clap:Parser::_help: use_long=true
DEBUG:clap:Parser::use_long_help: ret=false
DEBUG:clap:Help::write_parser_help;
DEBUG:clap:Help::write_parser_help;
DEBUG:clap:Parser::color;
DEBUG:clap:Parser::color: Color setting...Auto
DEBUG:clap:Help::new;
DEBUG:clap:Help::write_help;
DEBUG:clap:Help::write_default_help;
DEBUG:clap:Help::write_bin_name;
DEBUG:clap:Help::write_version;
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=verbose;
DEBUG:clap:Parser::groups_for_arg: name=verbose
DEBUG:clap:Parser::groups_for_arg: No groups defined
DEBUG:clap:usage::needs_flags_tag:iter: [FLAGS] required
DEBUG:clap:usage::get_args_tag;
DEBUG:clap:usage::get_args_tag:iter:binary path:
DEBUG:clap:Parser::groups_for_arg: name=binary path
DEBUG:clap:Parser::groups_for_arg: No groups defined
DEBUG:clap:usage::get_args_tag:iter: 1 Args not required or hidden
DEBUG:clap:usage::get_args_tag:iter: Exactly one, returning binary path
DEBUG:clap:usage::create_help_usage: pass through args has .last(true)
DEBUG:clap:usage::create_help_usage: usage=cargo flamegraph [FLAGS] [OPTIONS] [] [-- ]
DEBUG:clap:Help::write_all_args;
DEBUG:clap:Help::write_args;
DEBUG:clap:Help::write_args: Current Longest...2
DEBUG:clap:Help::write_args: New Longest...9
DEBUG:clap:Help::write_args: Current Longest...9
DEBUG:clap:Help::write_args: New Longest...9
DEBUG:clap:Help::write_args: Current Longest...9
DEBUG:clap:Help::write_args: New Longest...9
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=--help
DEBUG:clap:Help::spec_vals: a=--help
DEBUG:clap:Help::val: Has switch...Yes
DEBUG:clap:Help::val: force_next_line...false
DEBUG:clap:Help::val: nlh...false
DEBUG:clap:Help::val: taken...21
DEBUG:clap:Help::val: help_width > (width - taken)...23 > (175 - 21)
DEBUG:clap:Help::val: longest...9
DEBUG:clap:Help::val: next_line...No
DEBUG:clap:write_spaces!: num=7
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=--version
DEBUG:clap:Help::spec_vals: a=--version
DEBUG:clap:Help::val: Has switch...Yes
DEBUG:clap:Help::val: force_next_line...false
DEBUG:clap:Help::val: nlh...false
DEBUG:clap:Help::val: taken...21
DEBUG:clap:Help::val: help_width > (width - taken)...26 > (175 - 21)
DEBUG:clap:Help::val: longest...9
DEBUG:clap:Help::val: next_line...No
DEBUG:clap:write_spaces!: num=4
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=--verbose
DEBUG:clap:Help::spec_vals: a=--verbose
DEBUG:clap:Help::val: Has switch...Yes
DEBUG:clap:Help::val: force_next_line...false
DEBUG:clap:Help::val: nlh...false
DEBUG:clap:Help::val: taken...21
DEBUG:clap:Help::val: help_width > (width - taken)...22 > (175 - 21)
DEBUG:clap:Help::val: longest...9
DEBUG:clap:Help::val: next_line...No
DEBUG:clap:write_spaces!: num=4
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
DEBUG:clap:Help::write_args;
DEBUG:clap:Help::write_args: Current Longest...2
DEBUG:clap:OptBuilder::fmt
DEBUG:clap:Help::write_args: New Longest...19
DEBUG:clap:Help::write_args: Current Longest...19
DEBUG:clap:OptBuilder::fmt
DEBUG:clap:Help::write_args: New Longest...19
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=DEBUG:clap:OptBuilder::fmt
--frequency
DEBUG:clap:Help::spec_vals: a=DEBUG:clap:OptBuilder::fmt
--frequency
DEBUG:clap:Help::val: Has switch...Yes
DEBUG:clap:Help::val: force_next_line...false
DEBUG:clap:Help::val: nlh...false
DEBUG:clap:Help::val: taken...31
DEBUG:clap:Help::val: help_width > (width - taken)...50 > (175 - 31)
DEBUG:clap:Help::val: longest...19
DEBUG:clap:Help::val: next_line...No
DEBUG:clap:OptBuilder::fmt
DEBUG:clap:write_spaces!: num=4
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=DEBUG:clap:OptBuilder::fmt
--timeout
DEBUG:clap:Help::spec_vals: a=DEBUG:clap:OptBuilder::fmt
--timeout
DEBUG:clap:Help::val: Has switch...Yes
DEBUG:clap:Help::val: force_next_line...false
DEBUG:clap:Help::val: nlh...false
DEBUG:clap:Help::val: taken...31
DEBUG:clap:Help::val: help_width > (width - taken)...52 > (175 - 31)
DEBUG:clap:Help::val: longest...19
DEBUG:clap:Help::val: next_line...No
DEBUG:clap:OptBuilder::fmt
DEBUG:clap:write_spaces!: num=4
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
DEBUG:clap:Help::write_args_unsorted;
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=
DEBUG:clap:Help::spec_vals: a=
DEBUG:clap:Help::val: Has switch...No, and not next_line
DEBUG:clap:write_spaces!: num=4
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
DEBUG:clap:Help::write_arg;
DEBUG:clap:Help::short;
DEBUG:clap:Help::long;
DEBUG:clap:Help::val: arg=
DEBUG:clap:Help::spec_vals: a=
DEBUG:clap:Help::val: Has switch...No, and not next_line
DEBUG:clap:write_spaces!: num=7
DEBUG:clap:Help::help;
DEBUG:clap:Help::help: Next Line...false
DEBUG:clap:Help::help: Too long...No
cargo-flamegraph

USAGE:
cargo flamegraph [FLAGS] [OPTIONS] [] [-- ]

FLAGS:
-h, --help Prints help information
-V, --version Prints version information
-v, --verbose Prints out more stuff.

OPTIONS:
-f, --frequency The sampling frequency. By default, this is 99 Hz.
-t, --timeout Timeout in seconds. By default, there is no timeout.

ARGS:
The path of the binary to be profiled. If empty, Cargo.toml is searched for a binary.
... Any arguments you wish to pass to the binary being profiled.

[kbknapp]

Sorry for the long wait. Would doing this solve it?

 .arg(Arg::with_name("ARGS")
                .help("Any arguments you wish to pass to the binary being profiled.")
                .last(true)
                .multiple(true)
            )

Although this still probably a bug because it should be using the value name.

[golddranks]

That does its job the as a workaround, and actually this didn't provide any real problem to me 😄 I just thought this might be an unintended inconsistency, so I reported it.

[kbknapp]

2.24.1 is on crates.io