C Field has incomplete type, without forward declaration
<p>I keep getting the "field has incomplete type error," but I can't find any forward declarations for that type in my code, or for any of the types in it's struct--aside from pointer fields.  I tried recursive grep the folder, and still couldn't find any forward declarations.</p>

<p>How do I make GCC tell me where it thinks the forward declaration is? or why it's incomplete?</p>

<p>trying to compile this file:</p>

<p><a href="https://github.com/pdJeeves/CreaturesLib/blob/master/src/biochemistry/emitter.c" rel="nofollow">https://github.com/pdJeeves/CreaturesLib/blob/master/src/biochemistry/emitter.c</a></p>

<p>gets the error on this include:</p>

<p><a href="https://github.com/pdJeeves/CreaturesLib/blob/master/src/creature/creature.h" rel="nofollow">https://github.com/pdJeeves/CreaturesLib/blob/master/src/creature/creature.h</a></p>

<p>with the member</p>

<p>"struct Brain brain"</p>