fn last_error_frame(
filestore: &FileStore,
block_id: &str,
) -> Option<LastErrorFrame>Expand description
Read the bounded tail of block_id’s output file and return the
parsed LastErrorFrame if its last non-blank line is one. None
covers every other case (no such block, empty file, last line is
normal output, last line doesn’t parse as this exact frame shape) —
deliberately not distinguished further, since all of them mean the
same thing to a caller: nothing actionable to surface here.