pub fn widening_env(attempts: &[SourceAttempt]) -> Vec<&'static str>Expand description
Every environment variable the trace says would widen this search, in first-seen order and de-duplicated.
Built from the Disabled rows rather than from a separate registry, so
it cannot drift from what the run actually skipped: a source that was
consulted contributes nothing, and a source that was skipped contributes
exactly the variables its own row already names.
Order is the chain’s order, which is the order a user should set them in
(required_env documents the same for the multi-variable Tier-3 case).