lorri clobbers nix-shell environment

[rvl]

Describe the bug

I really like using lorri except for two problems that I have. The first is that it seems to be impossible to use nix-shell in a directory managed by lorri/direnv.

To Reproduce
Steps to reproduce the behavior:

1. Change to a project directory with lorri/direnv enabled.
2. nix-shell -p cmatrix
3. Run cmatrix -s, press key to exit.
4. touch shell.nix, wait a little for lorri daemon, press enter again.
5. Run cmatrix -s again ... it's disappeared!

Expected behavior

I would like it if lorri could not update variables, or somehow disable direnv temporarily, while a nix-shell is running.

Metadata

lorri 1.2.0 on NixOS.