LLD on proxy fails: "Value should be a JSON object."

[BP_Vital]

Hello there.
We have a custom LLD script running on Zabbix.3.2. Python script processes pre-generated CSV file, and prints out JSON for Zabbix LLD.
Everything works fine when it is running on a server.
However same script with same CSV fails on proxy.
Discovery rule fails with error "Value should be a JSON object" when being run on a proxy, i.e. assigned to proxy monitored host.
I can run it manually form proxy console, it prints out valid JSON (Validated on http://jsonlint.com).

What am I missing?

[nobodysu]

If you can run the script manually with success then the problem is in zabbix user environment variables, probably in PATH.
Determine your proxy PATH first:

echo $PATH

Then you can run script like this:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin script.py

[BP_Vital]

Thank you! Tweaking path variables solved this problem.