nautechsystems/nautilus_trader · error

default `PortfolioConfig` should be valid

Error message

default `PortfolioConfig` should be valid

What it means

Default for PortfolioConfig builds via the typed builder and unwraps, asserting the library's own defaults satisfy all builder validation rules. This panic indicates a library bug: the default configuration became invalid relative to its builder invariants.

Source

Thrown at crates/portfolio/src/config.rs:145

                errors.check(
                    ms > 0,
                    ConfigError::range(
                        field,
                        format!("must be a positive number of milliseconds, was {ms}"),
                    ),
                );
            }
        }

        errors.into_result()
    }
}

impl Default for PortfolioConfig {
    fn default() -> Self {
        Self::builder()
            .build()
            .expect("default `PortfolioConfig` should be valid")
    }
}

#[cfg(test)]
mod tests {
    use rstest::rstest;

    use super::*;

    #[rstest]
    fn test_default_config_is_valid() {
        assert!(PortfolioConfig::builder().build().is_ok());
    }

    #[rstest]
    fn test_default_config_enables_daily_equity_curve_only() {
        let config = PortfolioConfig::default();

View on GitHub (pinned to 18893faf8b)

Solutions

1. Update all nautilus crates to a consistent version (cargo update).
2. Reproduce with an explicit builder call to see which field fails validation.
3. Report as a library bug — the default must always be valid.

Example fix

// before
let config = PortfolioConfig::default(); // panics if defaults invalid
// after
let config = PortfolioConfig::builder()
    .build()
    .unwrap_or_else(|e| panic!("portfolio default invalid: {e}")); // inspect the failing field

// verify builder validity explicitly to surface the failing field
let cfg = PortfolioConfig::builder().build();
if let Err(e) = &cfg { eprintln!("portfolio config invalid: {e}"); }

let result = std::panic::catch_unwind(PortfolioConfig::default);

When it happens

Trigger: Calling PortfolioConfig::default() (directly or via ..Default::default() in configs) — panics only if the builder rejects the default field values, e.g. after a version change introduced new validated fields.

Common situations: Mixing crate versions (model/portfolio mismatch) where defaults no longer satisfy validation; a regression in the portfolio crate after adding a new required/validated config option.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• external message bus factory cannot be combined with injecte
• NautilusKernelBuilder cannot consume external message bus st
• default `StrategyConfig` should be valid
• Invalid config type for AxExecutionClientFactory. Expected A
• Invalid factory address for DEX {name} on chain {chain} for

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/f253a9a5f8f18370. Report an issue: GitHub.