Stack overflow when trying to upgrade to 20.03

[M-Gregoire]

Hello everyone,

I'm trying to upgrade from 19.09 to 20.03 but I'm encountering a weird issue.

I've changed my config according to the release note, updated my channels and tried nixos-rebuild switch --upgrade but I always get a stack overflow error.

--show-trace doesn't give any extra information.

I tried setting ulimit -s 100000 as per #42379 (comment) but it didn't work.

I also disabled every overlay that uses unstable after reading #84995 without success.

Weird thing is, I can deploy to another host (with nixops) which share a good part of my config but can't on this computer.

I'm not sure how I can diagnose this issue. Any idea?

Thank you for any help you can provide.

Error

sudo nixos-rebuild switch --show-trace --upgrade
building Nix...
building the system configuration...
error: stack overflow (possible infinite recursion)

Metadata

- system: `"x86_64-linux"`
 - host os: `Linux 5.4.33, NixOS, 19.09.git.b6c7259c4d0 (Loris)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.3.3`
 - channels(root): `"nixos-20.03.1422.1e90c46c2d9"`
 - channels(gregoire): `"nixos-20.03.1422.1e90c46c2d9"`
 - nixpkgs: `/path/to/nixpkgs-release`

[M-Gregoire]

I've been able to track down my issue to a self import in a file (https://github.com/M-Gregoire/infrastructure/blob/a4161867bedebc812c07d8b278e23b3b99a88dbb/home/home.nix#L10)...

I'm not sure why this was never a problem until 20.03 but at least it's fixed now!

Thank you for the work put in the release :)