Weird interaction: ECL throws errors on windows when TGUI tries to create an Edit Box

Question

I am currently using TGUI (a GUI library based on SFML) together with ECL (so I can use Lisp for config and scripts). It works fine on Linux/gcc, but on Windows/MinGW ECL throws an error:

Condition of type: FLOATING-POINT-INVALID-OPERATION
#<a FLOATING-POINT-INVALID-OPERATION>
Available restarts:

1. (CONTINUE) Ignore signal

Top level in: #<process TOP-LEVEL>.
>

The point in code at which the error is thrown (minimal code that creates it) is:

empty_panel = tgui::Panel::Ptr(*cur_gui, "empty_panel");
empty_panel->setSize(cfg.res.x, cfg.res.y);
empty_panel->setBackgroundColor(sf::Color::Transparent);

tgui::EditBox::Ptr txt_test(*empty_panel, "txt_test");

Note that I can create Labels, Buttons, Checkboxes, etc. just fine - but once I try to make an Edit Box, ECL complains. This does not make any sense to me whatsoever. TGUI and ECL are completely unrelated libraries, not sharing functions or depending on each other in any way that I know of. Does anyone have an idea what might cause this behavior?

EDIT: Just did a complete recompile of SFML, TGUI and ECL with the most recent version of MinGW, and it still breaks in exactly the same way. So I've decided that enough is enough and I'll rewrite my project to use SFGUI instead. From now on, this question is of academic interest only.

Answer 1

I finally found out what might have happened there:

While ECL is running, it tries to handle all uncaught exceptions, segfaults, etc that happen on it's watch, even if they never interact with LISP. And the way it handles them is by immediately jumping to the REPL when they occur, to allow for manual debugging.

Which is the sane thing to do for anything that happens because of errors in a LISP program or C/C++ functions that interact with it, but is mildly confusing when the error happens in unrelated C++ code (like the presumed bug in TGUI).

Minimal way to reproduce: Load ECL and try some invalid operation, like so:

#include <ecl/ecl.h>
int main(int argc, char **argv) {
cl_boot(argc, argv);
atexit(cl_shutdown);
int x = 1/0;
return EXIT_SUCCESS; }