motion-sqlite3 conflicts with ServiceManagement about motion-sqlite3

[mattgreen]

Post your Rakefile. I'm curious how you're calling SMLoginItemSetEnabled; I'm worried that motion.h is conflicting.

[JonasNielsen]

I tried including only motion.h without the gem but couldn't trigger the conflict. Can't tell what parts of motion-sqlite3 is causing the issue.

Here's a simple example project that demonstrates the issue: https://github.com/JonasNielsen/service-management-motion-sqlite3-conflict

Rakefile, Gemfile and app_delegate.rb

[mattgreen]

I love these weird bugs. This looks like a build system deficiency that's being exposed.

I think the problem is the app.include line in motion-sqlite3 (https://github.com/mattgreen/motion-sqlite3/blob/master/lib/motion-sqlite3.rb). When it runs, motion.h updates the BridgeSupport file list with a generated BridgeSupport file. However, the XcodeConfig object (https://github.com/HipByte/RubyMotion/blob/60cc0bf979c62d5b2e279eb26c9536ed16053dd5/lib/motion/project/xcode_config.rb) seems to only expect it's methods to be called after all frameworks have been declared. This makes it tough to use these methods from gems, since Bundler ensures that they get the first shot at RM config objects.

In other words, it's like ServiceManagement.framework never gets linked in because app.frameworks was updated after motion-sqlite3's use of app.include.

You can demonstrate this by updating the bug repo to muck with the Config object directly:
app.instance_variable_get(:@bridgesupport_files) << "/Library/RubyMotion/data/osx/10.9/BridgeSupport/ServiceManagement.bridgesupport"
app.instance_variable_set(:@frameworks_dependencies, nil)

This is a suitable short term hack, but it's horrible. The real fix is probably to incorporate motion.h's functionality directly into RubyMotion to avoid these sorts of issues.

Thoughts, @kastiglione and @lrz?

[JonasNielsen]

Yikes, that's hairy. Thanks for the help Matt, I really appreciate it. Your suggested workaround works well.

[vespakoen]

Hey guys,

Just a heads up that this also breaks 'CoreLocation', I got this error:

2014-05-28 00:26:07.496 abc[65287:70b] app_delegate.rb:4:in `application:didFinishLaunchingWithOptions:': undefined method `CLLocationCoordinate2DMake' for #<AppDelegate:0x9dbcb30> (NoMethodError)

Just spend a couple of hours debugging this, the trick was using rake clean:all before recompiling with a different set of gems, until I narrowed it down to motion-sqlite3.

I guess I will wait for a fix or try another sqlite project for now.

Thanks for the project, it is really nice to use, but this bug is a very hard one to debug, so I think a fix or a warning or something is in place.

[kastiglione]

I don't know when I'll actually get to it, but I'll create an issue on the motion.h repo to find out how it is breaking. It's doubtful I'll get to it before the second week of June.

[mattgreen]

I'm thinking it's better to not use motion.h for now.

I'll see if I can talk to Laurent or Eloy about getting RM to generate BridgeSupport files for SQLite.

[mattgreen]

Originally, I made motion-sqlite3 to see how viable RM's C FFI is. Answer: very. However, the BridgeSupport issue is enough for me to tank the idea. I think I'll move to exposing the SQLite API in a very low-level way via Obj-C, and then use that from Ruby.