Update README.md

modules/background_task/README.md

@@ -48,7 +48,7 @@ with-env { FOO: ($foo | to json) } {
 }
 ```
 
-## How can I reuse custom commands in a background task?
+### How can I reuse custom commands in a background task?
 
 You can define these commands in a seperate module, like so:
 
@@ -63,3 +63,6 @@ task spawn {
   foo bar
 }
 ```
+## Troubleshooting
+
+- On some setups (e.g. NixOS with `nu` installed as a binary in user's `$HOME`), `sh` (which `pueue` delegates tasks to run) might fail to find `nu` in the `$PATH`. In this case hard-coding the location of your nu binary in the `task spawn` function definiton in `task.nu` can solve the issue.