prepare_command in podspec doesn't execute in the correct directory

Question

I'm trying to execute a script from within prepare_command in my podspec. When I run pod install in the destination project directory the script is executed properly, but not in the project's Pods directory. Instead it's being run in Library/Caches/CocoaPods/Pods/...

I'm not using :path in the project's podfile, so it's not referencing the location of the podspec, but just the caches pods directory.

In my podspec it looks like this:

  s.prepare_command = <<-CMD
               ./updatePlist.sh
  CMD

I know that it's not happening in the right place because I'm having that updatePlist.sh add a couple of things in its directory, but they're only showing up in Caches/CocoaPods/Pods.