Conflicting types for `Sync'

[Michael Scott]

I just downloaded and tried to build Parrot and make failed with

In file included from include/parrot/pmc.h:18,
                 from include/parrot/parrot.h:250,
                 from imcc/imc.h:18,
                 from imcc/main.c:17:
include/parrot/thread.h:103: error: conflicting types for `Sync'
include/parrot/config.h:104: error: previous declaration of `Sync'
make: *** [imcc/main.o] Error 1
In config.h we have

typedef void SYNC;
typedef SYNC     Sync;
and in thread.h we have

typedef struct _Sync {
    Parrot_Interp owner;                /* that interpreter, that owns
                                           the arena, where the PMC is 
in */
    Parrot_mutex pmc_lock;              /* for wr access to PMCs 
content */
} Sync;

Forgive me if this is already known. My old G3 PB died some weeks ago 
and I've been somewhat disconnected. I just got the new one today, so 
hope to start on documentation duties next week.

Mike