This is what I get from fresh cvs code and your suggestion for dyngen-exec.h:
In file included from ../kpx_cpu/src/cpu/jit/basic-dyngen-ops.cpp:23:
../kpx_cpu/src/cpu/jit/dyngen-exec.h:101:2: error: #error Test
../kpx_cpu/src/cpu/jit/basic-dyngen-ops.cpp:33: warning: register used for two global register variables
../kpx_cpu/src/cpu/jit/basic-dyngen-ops.cpp:34: warning: register used for two global register variables
../kpx_cpu/src/cpu/jit/basic-dyngen-ops.cpp:35: warning: register used for two global register variables
make: *** [obj/basic-dyngen-ops.o] Error 1
The symptom was that SheepShaver closed before Mac OS 9.0.4 completed its boot up (its splash screen displayed and then SheepShaver closed).
I thought that symptom was mentioned in this thread, but maybe I got it mixed up with a different thread.
FYI: problem solved. I clicked the checkbox “Ignore Illegal Memory Accesses” using the preferences editor. After doing that, SheepShaver and Mac OS 9 launched successfully.