Solution

I've discovered that Flow CLI on MacOS machine had version 0.20.0, while one one Linux had latest (at time of this post) 0.24.0. Updating the version to latest solved the issue.

Case closed!

Problem

When Cadence scripts calls panic we are getting failed to encode value: unsupported value: <nil>, <nil> instead of actual error we see in emulator output. This behaviour I encounter on my Mac, but not on Linux machine...

Who is affected

Pretty much every developer who is using fcl and writes Cadence, since it's much harder to find where error occurred.

How to replicate

launch emulator with flow emulator -v
run script from root of this project node index.js

Expected outcome

[Error Code: 1101] cadence runtime error Execution failed:
error: panic: Uh-oh
 --> a0b8feeb4782c0bab8156663a881e3748f472f83332304cb593b15a45eaaeea7:2:16
  |
2 |                 panic("Uh-oh")
  |                 ^^^^^^^^^^^^^^

Below you can find screenshot from my Linux machine

Additional notes

I've seen this working just fine on my Linux machine returning [error code 1101] and then actual place where this is happening. Same package versions, Node v16.3.0.

MaxStalker / fcl-panic-result