Response 'debuginfo' never used with Pecan app

We're using wsme + pecan, integrated pecan like described in https://wsme.readthedocs.org/en/latest/integrate.html#configuration and currently 'debuginfo' is never filled with the exception traceback.

pip freeze | grep pecan
pecan==0.4.4
pip freeze | grep WSME
WSME==0.5b6

This definitely worked a few releases ago. As per initial investigation it is broken somewhere here
https://github.com/stackforge/wsme/blob/9546c1025057bf7d94ef3469a6bd26907fc7ca10/wsme/api.py#L202-L226