Function run_coupling_scoped 

pub fn run_coupling_scoped(
    db: &FactsDb,
    opts: &Options,
    changes_source: &str,
) -> Result<Vec<CouplingRow>>

Scoped variant of run_coupling: reads change history from changes_source instead of the opt-derived table. Used when a caller has already materialized a date-filtered view (changes_at_ts) and wants coupling restricted to that window. Does NOT memoize — the custom source is not covered by the standard CouplingMemoKey.

The changes_source overrides only the pair-source and Fisher-denominator tables; the internal good_commits revset is still built from the opt-derived table. That is equivalent to the primary path (no lineage, no time-bucket), where the cutoff window’s revset equals the full-history revset intersected with the window. Combined with --use-canonical-lineage or --time-bucket, the two diverge (pair paths use pre-rename names / bucketing reads full history); those combinations are out of scope here.

Errors

Returns CodeLoreError::Analysis on any SQL error.