$ ./configure --enable-jit
$ make

/bin/bash ../libtool --tag=LIBGST --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I.. -DDEFAULT_EXECUTABLE=\""/usr/local/bin/gst"\" -I../lib-src -I../lib-src -I../libffi/include -I../libffi/include -I../snprintfv -I../snprintfv -I../sigsegv/src -I../sigsegv/src -I../lightning -I../lightning -I.. -I.. -g -O2 -Wall -Wno-strict-aliasing -Wno-switch -fno-gcse -fstrict-aliasing -Wwrite-strings -Wdeclaration-after-statement -Wno-format -Wpointer-arith -Wno-pointer-sign -MT interp.lo -MD -MP -MF .deps/interp.Tpo -c -o interp.lo interp.c

gcc -DHAVE_CONFIG_H -I. -I.. -DDEFAULT_EXECUTABLE=\"/usr/local/bin/gst\" -I../lib-src -I../lib-src -I../libffi/include -I../libffi/include -I../snprintfv -I../snprintfv -I../sigsegv/src -I../sigsegv/src -I../lightning -I../lightning -I.. -I.. -g -O2 -Wall -Wno-strict-aliasing -Wno-switch -fno-gcse -fstrict-aliasing -Wwrite-strings -Wdeclaration-after-statement -Wno-format -Wpointer-arith -Wno-pointer-sign -MT interp.lo -MD -MP -MF .deps/interp.Tpo -c interp.c  -fPIC -DPIC -fomit-frame-pointer -o .libs/interp.o

In file included from interp.c:674:
prims.def: In function 'VMpr_String_ByteArray_asCData':
prims.def:4923: warning: value computed is not used
In file included from interp.c:677:
interp-jit.inl: In function '_gst_interpret':
interp-jit.inl:383: error: 'jb' undeclared (first use in this function)
interp-jit.inl:383: error: (Each undeclared identifier is reported only once
interp-jit.inl:383: error: for each function it appears in.)
make[3]: *** [interp.lo] Error 1
make[3]: Leaving directory `/usr/local/src/smalltalk-3.1/libgst'
make[2]: *** [all] Error 2
make[2]: Leaving directory `/usr/local/src/smalltalk-3.1/libgst'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/local/src/smalltalk-3.1'
make: *** [all] Error 2