# Pinned backend toolchain (step 1, 2026-09-19)

- qbe: /usr/local/bin/qbe, default target amd64_sysv
  (`qbe -h` offers amd64_sysv/amd64_apple/arm64/arm64_apple/rv64)
- cc: Debian 14.2.0-19 (assembler+linker for qbe output)
- gm2 (host compiler): GCC 16.0.1 experimental 20260325, flags `-fiso`
- Coco/R: CR V1.53 (Pat Terry, 2002), flags `-m -C`, `CRFRAMES=src/`

Re-verify with: `qbe -h`, `cc --version`, `gm2 --version`.
Self-host fixpoint (step 8) is defined over `.ssa` bytes; any qbe/cc
upgrade must keep the full suite green before updating this pin.