BoundaryML/baml · error

subsecond fits in u32

Error message

subsecond fits in u32

What it means

Internal invariant panic during PlainTime string formatting: the subsecond component ns % NANOS_PER_SECOND must be 0..999,999,999 and fit in u32 by construction; failure indicates broken arithmetic or corrupt internal state.

Solutions

1. Report to maintainers with the failing time value.
2. Rebuild the crate.
3. Avoid manual private-field construction of PlainTime.

fn plain_time_in_range(ns: i64) -> bool { (0..86_400_000_000_000).contains(&ns) }

std::panic::catch_unwind(|| plaintime_to_string(pt)).unwrap_or_else(|_| Err(FormatError::Internal))

When it happens

Trigger: Unreachable under normal operation; only via corrupted nanosecond values or changed constants.

Common situations: VM development, constant refactors, corrupted internals.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• hour fits in u8
• minute fits in u8
• second fits in u8
• block aware tail expression is not empty
• exhaustive realized-leaf template classification

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/9c1c213fe30700fa. Report an issue: GitHub.

Appendix: source

Thrown at baml_language/crates/bex_vm/src/package_baml/time.rs:437

            + i64::from(parsed.minute()) * NANOS_PER_MINUTE
            + i64::from(parsed.second()) * NANOS_PER_SECOND
            + i64::from(parsed.nanosecond());
        Ok(copy::time::PlainTime {
            _nanoseconds: time_ns,
        }
        .to_value(vm))
    }

    fn _to_string_impl(plaintime: &view::time::PlainTime<'_>) -> bex_str::BexStr {
        // Normalize manually-constructed out-of-range values into [0, 24h).
        let ns = plaintime._nanoseconds().rem_euclid(MAX_TZ_OFFSET_NS);
        let mut out = String::new();
        format_clock_into(
            &mut out,
            u8::try_from(ns / NANOS_PER_HOUR).expect("hour fits in u8"),
            u8::try_from(ns / NANOS_PER_MINUTE % 60).expect("minute fits in u8"),
            u8::try_from(ns / NANOS_PER_SECOND % 60).expect("second fits in u8"),
            u32::try_from(ns % NANOS_PER_SECOND).expect("subsecond fits in u32"),
        );
        bex_str::BexStr::from(out)
    }
}

#[allow(clippy::used_underscore_items)] // Autogenerated from private BAML fields
impl BamlClassTimeTimeZoneOffset for PackageBamlImpl {
    fn from_duration(vm: &mut BexVm, duration: &Value) -> Result<Value, VmRustFnError> {
        let nanos = {
            let instance = vm
                .as_instance(duration)
                .expect("TimeZoneOffset.from_duration: expected Duration instance");
            view::time::Duration { instance }._nanoseconds()
        };
        let offset_ns = i64::try_from(&*nanos)
            .ok()
            .filter(|ns| ns.abs() <= MAX_TZ_OFFSET_NS)
            .ok_or_else(|| {

View on GitHub (pinned to bd85ce9dee)