Looks like the recent ByteBuffer changes that were merged by @rurban are causing this.
Confirmed. With an all-g++ build, I get make test PASS at 81f3b68. But I get build failure at the merge commit 2b95094.
src/pmc/bytebuffer.c: In function 'void Parrot_ByteBuffer_set_string_native_orig(parrot_interp_t*, PMC*, STRING*)':
src/pmc/bytebuffer.c:540: error: invalid conversion from 'char*' to 'unsigned char*'
make: *** [src/pmc/bytebuffer.o] Error 1
In ByteBuffer.set_string_native make sure to use an unsigned char* in…
…stead of a regular char* to make g++ happy. Also, remove a superfluous GET_ATTR and const a local variable to make the optimizer slightly happier. Fixes #840. dukeleto++ for reporting the issue, kid51++ for alerting me about it.
When pkg-config not detected, set to 0.
For consistency with other header detectors, set HAS_LIBFFI to 0 rather than undef.