lorri daemon ignores shell.nix updates [macos]

[akrmn]

Describe the bug

Editing the shell.nix file for a project doesn't trigger a reload with the daemon. lorri watch does work, though.

I checked that the daemon is running with

# the daemon appears to be running:
$ launchctl list | grep lorri
3328	0	org.nixos.lorri

# this is all there is in the log:
$ cat /var/tmp/lorri.log
Oct 28 12:35:06.652 INFO ready

To Reproduce
Steps to reproduce the behavior:

1. cd my-project
2. wait for the first direnv: loading my-project/.envrc
3. edit my-project/shell.nix

Expected behavior
4. another direnv: loading ... is triggered

Actual behavior
4. Nothing happens.

Metadata

$ lorri info
lorri version: 312
Lorri Project Configuration

expression: /Users/moises.ackerman/git/my-project/shell.nix

$ uname -a
Darwin C02Z74ARLVDQ 19.6.0 Darwin Kernel Version 19.6.0: Mon Aug 31 22:12:52 PDT 2020; root:xnu-6153.141.2~1/RELEASE_X86_64 x86_64 i386 MacBookPro15,1 Darwin

Additional context
I installed following the instructions for macOS.

{
# these are the relevant lines in my `darwin-configuration.nix`:
  services.lorri.enable = true;
  services.lorri.logFile = "/var/tmp/lorri.log";
}

# and this is my `.envrc`:
source pre-lorri-setup.sh
eval "$(lorri direnv)"