Highlighting failed for a reason that is not a missing parser.
Lumis.highlight/2 returns this when the formatter, the annotations, the
render itself or the WASM runtime failed. Most of these are a caller mistake
that the options schema could not catch; :runtime is environmental.
Reasons
:formatter— the formatter could not be built, most often an unknown theme name:annotation— an annotation could not be composed onto the source:render— the formatter failed while writing its output:highlight— the highlighter itself failed:invalid_match_limit—budget: [match_limit: _]was outside1..65536:runtime— the WASM runtime could not be started or is unusable
The list is open, so a case over it needs a catch-all clause.