Crystal compile error

$ CXX=/usr/local/bin/clang++ CC=/usr/local/bin/clang gmake                                                    
Using /usr/local/bin/llvm-config [version=4.0.0]
/usr/local/bin/clang++ -c  -o src/llvm/ext/llvm_ext.o src/llvm/ext/llvm_ext.cc `/usr/local/bin/llvm-config --cxxflags`
warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option]
1 warning generated.
/usr/local/bin/clang -fPIC    -c -o src/ext/sigfault.o src/ext/sigfault.c
ar -rcs src/ext/libcrystal.a src/ext/sigfault.o
CRYSTAL_CONFIG_PATH=`pwd`/src ./bin/crystal build  -o .build/crystal src/compiler/crystal.cr -D without_openssl -D without_zlib
Invalid memory access (signal 11) at address 0x7f7fffbefff8
[0x126cb6138336] *CallStack::print_backtrace:Int32 +118
[0x126cb6113b1d] __crystal_sigfault_handler +61
[0x126f6a346002] ???
gmake: *** [Makefile:114: .build/crystal] Error 11