And yes, those are different things. One describes the version of the headers you are using and the other describes the version of the libmirclient binary that you are using. Usually they will be equal, but the point of bug 1195540 is to cover cases where you want to dynamically bind to new API functions at runtime.
I think you can safely skip Brandon's comment because it's not relevant to the final solution. All we need is:
unsigned mir_get_ client_ api_version( ) API_VERSION;
{
return MIR_CLIENT_
}
And yes, those are different things. One describes the version of the headers you are using and the other describes the version of the libmirclient binary that you are using. Usually they will be equal, but the point of bug 1195540 is to cover cases where you want to dynamically bind to new API functions at runtime.