That error potentially suggests your SDL version is less than 2.0.10 - or that my program isn't finding the correct version of SDL2 on your system. Either way it's a helpful lead! It might be worth updating SDL2, and probably SDL2_image and SDL2_mixer, if you do have a lower version and this applies.
Viewing post in I'll Cut You Down jam comments
HasIntersectionF is only in SDL2 2.0.22, so this would definitely contribute to the game not working! To save you the hassle of upgrading ahead of your distro, I think I can quickly rework the hitbox code to use the older, more compatible SDL2 variant - I'll post soon and let you know how I went. Thanks for being so patient!
Here is a version of 'icyd' without the use of SDL's floating point rectangles. I can't promise I didn't introduce exciting new bugs by rushing my own rectangle code ;)
https://diablerie.itch.io/extra-files/download/jNVGVPB5N36vC2k6_KTTG67_WN6NMKs__...
I am terribly sorry, but now I get:
./icyd: symbol lookup error: ./icyd: undefined symbol: Mix_PlayChannel
My libsdl2-mixer is version 2.0.4, if that's relevant. I do enjoy the large amount of support and users of Ubuntu based distros, but it must kind of sucks (at least for developers) when everyone stuck with old libraries like these.
I need to sleep, so I won't be able to respond for a few hours. I'm sorry. You've been so responsive, so I wish I could have voted for your game. Good night!
I understand, and I'm sorry I couldn't get it to work. There are a couple of ways I might have been able to detect and fix these kind of version errors, so I'll make sure to implement them in our post-jam version of the game. It's a good learning experience for me, and I'm really grateful you've helped me identify a few more technical issues. Goodnight, and thanks again for persevering!
Oh, and in case you were curious, I can confirm that error is also SDL2 version related. The game uses features from SDL2_mixer 2.6.0 (the current version is 2.6.3), and missing those features will be much harder to work around than the rectangles :(