How to repair warning: missing braces around initializer?

Yes, this appears to be related to GCC bug 53119. It goes away if you change the C declaration to {{0}}. Your options are:

1. Ignore the warning.
2. Manipulate the C code after generation to have {{0}} instead of {0} on that line using sed or the like.
3. Declare the array extern in Vala, and write the C definition elsewhere. (The permanent version of #2.)
4. Do something like struct foo { int bar; Position positions[8]; } static foo position_holder and {0} will then be initialising position_holder.bar which is fine and the warning goes away.