noyalib
The noyalib rosette mark on a dark ground.

Release · 7 September 2026

noyalib v0.0.39

Twenty documents, each built to break one part of a YAML parser, are now fixtures. Three of them broke this one, and those defects are fixed.

By , maintainer of noyalib and its five companion crates. Last reviewed .

What changed

A reader sent twenty YAML documents designed to find the edges of the specification. Every expectation for them was checked against libyaml and go-yaml before it became a test, so the suite records what the three implementations agree on and where they part company.

Fixed

  • The parallel path counted one document too many for any stream that opened with a comment, a blank line or a directive. The splitter treated that prologue as a document of its own, so it disagreed with the ordinary loader about the shape of the stream. A property test now holds the two to the same answer across every file of the official test suite and every fixture.
  • A self-referential anchor was described wrongly. An alias pointing at an anchor still being built was reported as an unknown anchor defined "in an earlier document", which is nonsense in a single-document file. It now names the real limit: YAML's representation graph may be cyclic, and a parsed value is a tree.
  • An !!int in a YAML 1.1 spelling now explains itself. !!int 0b101010 answers "YAML 1.2 has no binary literal, 0b was YAML 1.1; write 42".

Where the implementations disagree

  • The billion-laughs payload, seven levels of ten-fold alias expansion, is refused here in well under a second by the alias budget. Under a two-gigabyte cap libyaml exhausted memory and go-yaml had not finished after a minute.
  • The Norway problem. Under YAML 1.2's core schema NO, no, on, off, y, n and 190:20:30 are all strings, and this release proves it case by case. libyaml still reads them the 1.1 way and turns NO into false and 190:20:30 into 685230.

Upgrading

Bump every noyalib crate you use to 0.0.39. No public API changed shape.