Using mkIf with nested if

Help
4

I still do not really understand why it behaved this way ?

I tried to explain why it works like this in Best resources for learning about the NixOS module system? - #3 by teto

I have the feeling that the mkIf expression is still evaluated even if the flag is set, right

right.

So what can be done:

  • you may set _module.check = false;, then it won’t complain about this kind of problems. It is bad, because when you do typos in option names, it won’t detect those typos
  • you may add an explicit variable load. For example, add to each module:
    let home-manager = builtins.getEnv "IS_HOME_MANAGER_EVAL" == "yes"; in
    This way resolving home-manager doesn’t require module system eval, so it won’t cause infinite recursion. Now all you have to do is export IS_HOME_MANAGER_EVAL=yes before home-manager rebuilds.
  • best is to split system config and home configs and don’t try to mix that
  • or mix those correctly. I’ve seen that @Infinisil had merged those nicely in GitHub - infinisil/system: My system configuration. For example, here is how system service and home.packages are intermixed. Check this file for how to add home-manager module.
1 Like