I am trying to debug a bug in racket that only occurs under NixOS. I am new to NixOS. Is there a quick way to get a NixOS image where I can compile and debug? I was thinking of docker but can’t find any NixOS docker image. Have I missed anything?
The short version: nixos won’t run on docker properly (without --privileged or similar concessions) because it needs systemd. I’d recommend a VM or live system instead, which you can set up using one of the images on Download Nix / NixOS | Nix & NixOS.
I’m not sure of the specifics of the bug, but maybe you can also reproduce it with the racket from nixpkgs on another distribution or in the nix docker image.
I am trying to reproduce this:
https://github.com/racket/racket/issues/2451
Reproducing is actually ok, because I can just install racket and run it to check. But now I need a debuggable version. I need to build racket under nix and then run it under gdb to understand what’s happening. Similar to what Mic92 did on the bug report.
I guess I might need a VM then…
than indeed, you should download a VM image just like @lheckemann described. Also, you can install Nix locally and generate NixOS VM images yourself with https://github.com/nix-community/nixos-generators.
And finally, you can install additional packages (like gdb) in Docker as well. Just add -p gdb to command line (dunno how well gdb works in docker). You may also run in Docker
$ nix-shell '<nixpkgs>' -A racket
nix-shell $ unpackPhase
to fetch sources and builders. Then reconfigure and rebuild racket as usual
You may also be interested in current build instructions. They lay at https://github.com/NixOS/nixpkgs-channels/blob/5e6ae9b6a51a1ab4a182b23f5bc883e4ae7f6692/pkgs/development/interpreters/racket/default.nix