[rscorer]

Problem

When either both chrono and time, or bigdecimal and rust_decimal features are active in the build graph, setting an explicit preferred crate in sqlx.toml still causes query!() macros to emit warnings warn_on_ambiguous_inferred_date_time_crate / warn_on_ambiguous_inferred_numeric_crate.

Analysis

In sqlx-core/src/type_checking.rs, the branches for DateTimeCrate::Time and NumericCrate::BigDecimal check:

#[cfg(feature = "time")]
if matches!(preferred_crates.date_time, DateTimeCrate::Time | DateTimeCrate::Inferred) {
    ...
    if cfg!(feature = "chrono") {
        return Err(Error::AmbiguousDateTimeType { ... });
    }
}

Because cfg!(feature = "chrono") was checked unconditionally inside the matches!(..., Time | Inferred) block, setting date-time = "time" still returned AmbiguousDateTimeType.

The same issue affected param_type_for_id and return_type_for_id for both DateTimeCrate::Time and NumericCrate::BigDecimal.

Solution

Only return AmbiguousDateTimeType / AmbiguousNumericType if preferred_crates.{date_time,numeric} is Inferred:

 if preferred_crates.date_time == DateTimeCrate::Inferred && cfg!(feature = "chrono")

and

if preferred_crates.numeric == NumericCrate::Inferred && cfg!(feature = "rust_decimal")

Unit tests have been added in sqlx-postgres verifying that explicit crate selections succeed when both conflicting crate features are enabled in the build graph.