Change -o0 to -O0

[NQNStudios]

I've only tested this change on Linux. Does CI run a debug build? If so, it'll determine whether this change works on other platforms.

Fixes #343

[CelticMinstrel]

Does CI run a debug build?

That's… a good question? I think it doesn't, but presumably you can examine the CI scripts to check.

The change shouldn't affect Windows+Cl, and if it works on Linux it should be fine on both Mac+scons and Windows+MinGW (though the latter isn't yet officially supported). And it obviously has no effect on non-scons builds.

…although, looking at that file you edited, it's probably incorrect for a Windows+Cl build both before and after this change, as Cl does not understand the -g or -O flags at all. Unless scons is able to automatically correct for that somehow.

[NQNStudios]

Looking at the github action logs, here's what I learned:

• None of them pass debug=true to scons. And I think that's a good thing because ultimately we want to know whether the release build works, and we don't want to wait for it to build one of each. But we should manually test debug=true for scons on every platform, and possibly also open the binaries in a debugger and make sure they're debuggable. This PR accomplishes that on Linux.
• Win scons is actually failing silently before it even starts a build: https://github.com/calref/cboe/actions/runs/4088304638/jobs/7051667263#step:5:11
  • It's failing to source vcvarsall.bat
  • Was win-scons even enabled in the actions until very recently?

Should I figure out what flag the Windows+Cl compiler uses for debug and add it in an if windows statement? I might not be able to test scons on Windows, I haven't gotten it working locally yet.

[CelticMinstrel]

Was win-scons even enabled in the actions until very recently?

It's been enabled for quite awhile. I'm pretty sure it was even working when the MSVC build was failing.

Should I figure out what flag the Windows+Cl compiler uses for debug and add it in an if windows statement?

It might be nice but I think it's not crucial to have. Note that "if windows" is not enough – you need to check for the msvc toolchain as well. If it were Windows+MinGW then that uses GCC and the flags are the same as other platforms.

I might not be able to test scons on Windows, I haven't gotten it working locally yet.

That might be because of the vcvarsall.bat nonsense to bring the build tools into %PATH%. The easiest way to make that work if building manually would probably be to use a "Visual Studio Command Prompt", which basically sets that all up for you so that all the build tools are already in %PATH%. It can be launched from inside Visual Studio from one of the menus. There may also be a shortcut to launch one without opening Visual Studio.

But we should manually test debug=true for scons on every platform

scons currently doesn't work at all for me on the Mac, though I think that's only because I have SFML installed in framework format and it expects bare dynamic libraries. I suppose I could try installing those (even though it's kinda redundant) and see if it works that way. It would be kind of nice if this was a configurable option in scons but actually making that so doesn't feel worthwhile when no-one is even using scons on a Mac.

[CelticMinstrel]

By the way, I believe the MSVC Cl flags equivalent to -g -O0 would be /Zi /Od.