With your changes I'm able to run the examples, but running fire.cr in release mode doesn't work for me:

➜  crystal git:(bf33cea) bin/crystal samples/sdl/fire.cr --release       
Using compiled compiler at .build/crystal
Invalid memory access (signal 11) at address 0x4
[4283462] ???
[4278302] __crystal_sigfault_handler +30
[4283736] sigfault_handler +40
[139807178141824] ???
[4218555] ???
[4277579] main +43
[139807165575825] __libc_start_main +241
[4203226] _start +42
[0] ???

➜  crystal git:(bf33cea) llvm-config --version
3.9.0

➜  crystal git:(bf33cea) uname -a
Linux marcos-macbook-arch 4.4.38-1-lts #1 SMP Sat Dec 10 20:21:58 CET 2016 x86_64 GNU/Linux

➜  crystal git:(bf33cea) sdl2-config --version
2.0.5

Interesting. All it did for me is add performance.

Testing on fresh VM install.

 $ lsb_release -d
 Description:	Ubuntu 16.04.1 LTS
 $ uname -a
 Linux ubuntu 4.4.0-53-generic #74-Ubuntu SMP Fri Dec 2 15:59:10 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

 $ bin/crystal samples/sdl/fire.cr 
 2132 frames in 6051 ms
 Average FPS: 352.33845645347873

 $ bin/crystal samples/sdl/fire.cr  --release
 16600 frames in 10221 ms
 Average FPS: 1624.107230212308

 $ llvm-config --version
 3.8.0

 $ sdl2-config --version
 2.0.4

Did these samples work for you without my changes? I have no way to test on a mac right now.

Did these samples work for you without my changes? I have no way to test on a mac right now.

No, they were not working. They are working with your changes in my linux machine (my mac runs linux, not osx) with the exception of fire.cr in release mode.

Seems like you are using your locally compiled crystal, which seems to have some kind of problem.

rm -r .build and then retry, should work as i see no issues with the code right now or was able to replicate the issue.

This is a small change, what is taking so long? Broken samples are rather discouraging for people new to crystal.

I think it's better if we remove these samples and move them to, maybe, https://github.com/ysbaddaden/sdl.cr

It's taking some time because:

• it used to work the way it is (at least for some people);
• I don't have to call SDL_main on Linux (as per documentation), but I know nothing about other platforms; I don't have a Mac at hand for example;
• it's not critical to Crystal (compiler, core/std lib).

Last but not least: the samples are for SDL 1.2, not SDL 2 as far as I know, and both versions sre quite different.

I think the Crystal-lang team have done a great job and more than deserve some time off to spend w/ family this holiday season! Merry [belated] Christmas and Happy New Year!

Indeed, happy new year!

Closing this. Samples on master still exist and fail, but i see no interest in this PR.