nix-eda-packaginglisted

# Nix EDA Packaging ## Overview EDA tools are awkward Nix citizens: they dlopen plugins at runtime, expect data files at fixed paths, and ship as prebuilt binaries with bad assumptions about the filesystem. The temptation is to paper over each failure with a wrapper or a binary patch. The discipline is to fix the actual dependency so the package is honest about what it needs. **Core principle:** Make the package's real dependencies explicit, don't disguise them. A `wrapProgram` that injects a path or a `patchelf` that rewrites an interpreter hides a missing dependency instead of declaring it, and it breaks the next person who builds on your package. ## When to Use - Packaging Yosys, OpenROAD, a simulator, or a vendor EDA binary in Nix - A tool fails at runtime to dlopen a plugin or find a shared library - Writing derivations and build phases for hardware tooling - Building/evaluating on aarch64-linux ## Don't Reach For The Hacks These are the moves to avoid, and what they're hiding: - **`wrapProgram` to inject `LD_LIBRARY_PATH` / plugin paths.** Hides a real missing runtime dependency. The library belongs in `buildInputs` and on the proper rpath, or the plugin belongs in a declared search path the program already honors. - **`patchelf` to rewrite the interpreter or rpath by hand.** Hides a build that didn't link correctly. Fix the link, or for unbuildable prebuilt blobs use the proper mechanism (`autoPatchelfHook`) only as a last resort and only for genuinely closed b