Function rustc_mir_build::thir::pattern::check_match::const_not_var

fn const_not_var(
    err: &mut Diagnostic,
    tcx: TyCtxt<'_>,
    pat: &Pat<'_>,
    path: &Path<'_>
)

A path pattern was interpreted as a constant, not a new variable. This caused an irrefutable match failure in e.g. let.