Lambda Language Compiler Achieves Self-Hosting Bootstrap After Fixing Hidden Bugs

A small low-level language called 'lm' with four backends — C, WebAssembly, ARM64, and a bytecode VM — has reached a self-hosting milestone, where its compiler can reproduce itself byte-for-byte across build stages. The project's 94-test suite, while robust for cross-backend consistency checks, could not verify whether the lm-written compiler agreed with its own output, a gap that bootstrapping was designed to close. To confirm correctness, the compiler was built through successive stages until stage3 and stage4 produced identical 7,023-line outputs. The process uncovered two bugs invisible to the existing test suite: an ARM64 register corruption during large memory moves, and a Node.js pipe-buffering issue that silently truncated output exceeding a few thousand lines. Both flaws only surfaced when the compiler processed its own substantially larger source files, highlighting the limits of small-scale test corpora for validating self-hosting compilers.