Crash in `::trace`

[obycode]

Describe the bug There is a bug in ::trace causing a crash.

To Reproduce Steps to reproduce the behavior:

1. git clone https://github.com/obycode/trace-bug.git
2. cd trace-bug
3. clarinet console --use-on-disk-deployment-plan
4. In the console, run ::trace (contract-call? .caller call-latest u4)

Expected behavior This should successfully trace the execution and not cause the console to crash.