Debian Testing and PLPG-Debugger error. My fault or something else?

Hello everybody.
On a Debian testing 32 bit with PostgreSQL 9.5 installed from the
PostgreSQL "Jessie" official repository I have installed the debugger
for debugging Pl/PGSql functions.

Same thing with PgAdminIII 1.22 installed from the same repository.

Everything is fine but when I click "debug" on any function i receive
the error I link here: http://pasted.co/dd8efb22

The problem is not urgent and I am not blocked because I can click
"continue" and the debugger works flawlessly.

It's only pure curiosity.

Thank you.