Bad error message for non existing data source

[m1n0]

soda scan -d does_not_exist -c configuration.yml checks.yml

results in

Soda Core 3.0.0b4
Unknown error while executing scan.
  | dictionary changed size during iteration
  | Stacktrace:
  | Traceback (most recent call last):
  |   File "/Users/m1n0/dev/soda/soda-sql/soda-core/soda/core/soda/scan.py", line 267, in execute
  |     for data_source_scan_cfg in self._sodacl_cfg.data_source_scan_cfgs.values():
  | RuntimeError: dictionary changed size during iteration

[tombaeyens]

Data source "does_not_exist" does not exist. should be added as an error to the logs.
No stack trace should be shown (unless -V).