How to disable interactive debugger (to avoid segfault when no TTY)

Help!
#1

I’m using the foreign language interface. It seems that the engine segfaults when entering the interactive debugger (in my case, calling pyswip’s Prolog.assertz("a23123 s 1/0") ). It does this in when run within IntelliJ’s PyCharm IDE. The problem goes away when I ask PyCharm to “emulate terminal in output console”.

I don’t really need the interactive debugger. I thought I could disable it with “–tty=false” or “–no-tty” to the PL_initialize call. These make no difference. Should I expect that these options would disable the debugger?

#2

It shouldn’t enter the debugger on exceptions as long as you catch them (provided the Python interface passes on the Prolog exception). In some cases the debug_on_error flag could help, but it was more relevant in the days the system didn’t have exception handling :slight_smile: .

#3

Python does can catch and pass on the prolog exception. The debugger is entered before the Python receives it.

I guess its more of a compiler/syntax error.

Executing (via pyswip) Prolog.query(mod1:(assertz((a23123 s 1/0))).` enters a prompt:

Call: (1) pyrun("mod1:(assertz((a23123 s 1/0))).", _2798) ?

and typing h

Options:
+:                  spy        -:              no spy
/c|e|r|f|u|a goal:  find       .:              repeat find
a:                  abort      A:              alternatives
b:                  break      c (ret, space): creep
[depth] d:          depth      e:              exit
f:                  fail       [ndepth] g:     goals (backtrace)
h (?):              help       i:              ignore
l:                  leap       L:              listing
n:                  no debug   p:              print
r:                  retry      s:              skip
u:                  up         w:              write
m:                  exception details
C:                  toggle show context

… is managed by libswi.

FYI. I’m a little tied the foreign interface since I need some matrix-heavy computation to be performed interactively as a foreign predicate (I understand its possible to link swipl against a foreign .so – however, driving from another language provides us a lot more flexibility).

#4

This probably means that the python wrapper around Prolog doesn’t tell Prolog it is willing to handle exceptions (see PL_open_query() flags). If Prolog finds itself in the situation where it has an open exception and nobody willing to handle it, it will by default start the debugger.