Polyapps can be incompatible (crash) across Player versions

[mcclure]

I built a version of Polycode c3c534c with very minor patches. I then created a polyapp using the polybuild included therein. The polyapp uses the 2D Physics module; you can find it inside of the package of this StandalonePlayer http://www.glorioustrainwrecks.com/files/UnplayableAsteroidsMac.zip or source code at https://bitbucket.org/runhello/luatest .

If I run this Polyapp I built using the stock 0.8.2 Polycode Player downloaded from the website, on any machine, it crashes with a segfault: http://pastie.org/2896232

Unless something is wrong with my build process (unlikely; I'm using the build script inside the "luatest" project linked above, which is in lockstep with BUILD.md plus what Ivan said about the standalone/ directory) it appears that a polyapp built using a post-0.8.2 version of Polycode (at least with modules; I have not tested a module-less polyapp) when run with 0.8.2, will cause a crash. One of two fixes, if possible both, is needed.

• Make it not do that
• Because it is apparently possible for a polyapp run with the "wrong" PolycodePlayer to crash, add some kind of "requires-version" field to the Polyapp so that a 0.8.3 polyapp run on a 0.8.2. player will produce a "This polyapp is not compatible" dialog and not a crash.