### What does this PR do?
Adds [@mschwarzl's Fuzzilli Support
PR](https://github.com/oven-sh/bun/pull/23862) with the changes
necessary to be able to:
- Run it in CI
- Make no impact on `debug` and `release` mode.
### How did you verify your code works?
---------
Co-authored-by: Martin Schwarzl <mschwarzl@cloudflare.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>
Provides a Nix flake as an alternative to `scripts/bootstrap.sh` for
setting up the Bun development environment.
## What's included:
- **flake.nix**: Full development environment with all dependencies from
bootstrap.sh
- LLVM 19, CMake 3.30+, Node.js 24, Rust, Go
- Build tools: ninja, ccache, pkg-config, make
- Chromium dependencies for Puppeteer testing
- gdb for core dump debugging
- **shell.nix**: Simple wrapper for `nix-shell` usage
- **cmake/CompilerFlags.cmake**: Nix compatibility fixes
- Disable zstd debug compression (Nix's LLVM not built with zstd)
- Set _FORTIFY_SOURCE=0 for -O0 debug builds
- Downgrade _FORTIFY_SOURCE warning to not error
## Usage:
```bash
nix-shell
export CMAKE_SYSTEM_PROCESSOR=$(uname -m)
bun bd
```
## Verified working:
✅ Successfully compiles Bun debug build
✅ Binary tested: `./build/debug/bun-debug --version` → 1.2.24-debug
✅ All dependencies from bootstrap.sh included
## Advantages:
- Fully isolated (no sudo required)
- 100% reproducible dependency versions
- Fast setup with binary caching
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
