[Solved]Help bring a Guile game to live

Programming
1

Hi

I am working on a game

Now I am stuck at debug it because the segment fault:

Could someone in the community guide?

Thank you.

2

Have you tried using a debugger? Also, a coredump would be more helpful than a stacktrace.

That being said, how would one reproduce the issue? Could you add the complete step and required packages? That would reduce the friction for contributors :slight_smile:

3

Looking through the savannah repo - the sources are pretty old (2008-2012). It’s likely written targeting guile 2 or likely even an earlier release. Are you trying to run it with guile 3?

4

This is a guess. The code uses sdl1.2 and (use-modules (system foreign)) is used for the bindings. Maybe that part of the code could be replaced by using guile-sdl2.

5

The compile and build follows:

  1. ./configure
  2. make

run it
cd src
./ballandpaddle

The crash happenes right after.

I could not make Guile debugger work for it so I got the strace and put it in the issue.

6

I have tried both Guile 2 and Guile 3. The result is the same.

It used to run for Guile 3 under Debian GNU/Linux 10, and now it crashes in Debian 11.

7

sdl1.2 and sdl2 are not compatible, and it is not straight to make the change.
The game used to work under sdl1.2 and Debian GNU/Linux 10 so to make it work at sdl1.2 and Debian 11 should be the first step.

8

In your s-trace it says right before the SIGSEGV you don’t have the splash asset at the expected path:

openat(AT_FDCWD, "/usr/share/ballandpaddle/images/splash.png", O_RDONLY) = -1 ENOENT (No such file or directory)

Looking at the scheme code it has hard coded paths to /usr/share that aren’t injected using autoconf. I copied the assets to the right spot it started for me.

ballandpaddle is just a scheme file. To debug it - you can start guile and load that file manually into the REPL . Alternatively, you can also start guile via gdb then load it and you’ll get at least a partial backtrace into the FFI. That points to SDL_DisplayFormatAlpha which coincides with a image loading. The game doesn’t appear to test if assets exist before trying to load them.

2 Likes
9

Thank you very much.
Now I have I know how to debug it.

This issue can be considered closed.