cannot combine {flag} with an inline {key} option for {}

Error message

cannot combine {flag} with an inline {key} option for {}

What it means

The tool was invoked with inline options embedded in the tool string (e.g. `node[a=b]`) and additionally the same key was passed via a flag (--tool-option/--env, tracked by `flag`). request_options() refuses the ambiguous combination when the key already exists in the tool's explicit_opts().

Source

Thrown at src/cli/use.rs:222

                .and_then(|mut table| table.remove("value"))
                .unwrap_or_else(|| toml::Value::String(value.to_string()));
            entries.push((key.to_string(), value, "--tool-option"));
        }
        let mut seen = std::collections::HashSet::new();
        for (key, value, flag) in entries {
            if !seen.insert(key.clone()) {
                bail!(
                    "tool option {key:?} was specified more than once for {}",
                    self.tool
                );
            }
            if self
                .tool
                .ba
                .explicit_opts()
                .is_some_and(|options| options.contains_key(&key))
            {
                bail!(
                    "cannot combine {flag} with an inline {key} option for {}",
                    self.tool
                );
            }
            options
                .insert_option(key, value)
                .map_err(|error| eyre!(error))?;
        }
        Ok(options)
    }
}

impl Use {
    pub(super) fn is_dry_run(&self) -> bool {
        self.dry_run || self.dry_run_code
    }

    pub(crate) async fn run(mut self) -> Result<()> {

View on GitHub (pinned to afd2eddd3a)

Solutions

Remove the inline option from the tool string and keep the flag.
Or remove the redundant --tool-option flag and rely on the inline option.

Example fix

// before
mise use 'node[cache=true]' --tool-option cache=false
// after
mise use node --tool-option cache=false

Defensive patterns

Strategy: validation

Validate before calling

[[ "$tool" == *'['*']' ]] && echo 'inline options present; do not pass --tool-option for the same keys'

Prevention

Pick one style: inline bracket options OR --tool-option flags, not both for the same key.
When wrapping mise use, detect bracketed tool syntax and skip flag options.
Standardize the team's option mechanism in docs.

When it happens

Trigger: `mise use 'node[opt=x]' --tool-option opt=y` — the key `opt` present in ba.explicit_opts() collides with the flag-provided key in request_options().

Common situations: Mixing bracketed inline tool options with --tool-option flags; extending an existing command line by appending a flag without noticing the inline options.

Related errors

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/4766ae7eb368b96d. Report an issue: GitHub.