Custom Package - PostProcessBuild

I'm trying to build a custom package for iOS that uses the PostProcessBuild attribute to modify the Xcode project it's generating. The code works fine when not in a package, but when putting it into the package it can't find the UnityEditor namespace, during the build process.

Is there an assembly reference I can add to the asmdef file to make it work? The code is sitting in a root Editor folder of the package already, with an asmdef file as well.

 

It seems to be the asmdef file creating the issue, which from what I understand is required for a package. If I move the folder out of the package into the the project directly and remove the asmdef it works properly. I'm not seeing any way to include a reference to the UnityEditor though.

 

Ah ok, I was using the "Any" platform selection, If I change it to just Editor that appears to still work and fix the issue, thanks!