Build failure on OSX 10.11

[gcr]

This library doesn't build properly with clang 7.0.2 on OSX:

$ luarocks install nixio OPENSSL_DIR=/usr/local/Cellar/openssl/1.0.2d_1/
Installing https://raw.githubusercontent.com/rocks-moonscript-org/moonrocks-mirror/master/nixio-0.3-1.src.rock...
Using https://raw.githubusercontent.com/rocks-moonscript-org/moonrocks-mirror/master/nixio-0.3-1.src.rock... switching to 'build' mode
mkdir -p dist/usr/local/share/lua/5.1
cp -pR lua/* dist/usr/local/share/lua/5.1 2>/dev/null || true
for i in $(find dist -name .svn); do rm -rf $i || true; done
env MACOSX_DEPLOYMENT_TARGET=10.8 gcc  -O2 --std=gnu99 -Wall -Werror -pedantic  -O2 -fPIC -I/Users/michael/local/torch/install/include -fPIC -c -o src/nixio.o src/nixio.c
env MACOSX_DEPLOYMENT_TARGET=10.8 gcc  -O2 --std=gnu99 -Wall -Werror -pedantic  -O2 -fPIC -I/Users/michael/local/torch/install/include -fPIC -c -o src/socket.o src/socket.c
env MACOSX_DEPLOYMENT_TARGET=10.8 gcc  -O2 --std=gnu99 -Wall -Werror -pedantic  -O2 -fPIC -I/Users/michael/local/torch/install/include -fPIC -c -o src/sockopt.o src/sockopt.c
env MACOSX_DEPLOYMENT_TARGET=10.8 gcc  -O2 --std=gnu99 -Wall -Werror -pedantic  -O2 -fPIC -I/Users/michael/local/torch/install/include -fPIC -c -o src/bind.o src/bind.c
src/bind.c:259:30: error: 'memcpy' call operates on objects of type 'nixio_sock'
      (aka 'struct nixio_socket') while the size is based on a different type 'nixio_sock *'
      (aka 'struct nixio_socket *') [-Werror,-Wsizeof-pointer-memaccess]
        memcpy(clsock, sock, sizeof(clsock));
               ~~~~~~               ^~~~~~
src/bind.c:259:30: note: did you mean to dereference the argument to 'sizeof' (and multiply it by
      the number of elements)?
        memcpy(clsock, sock, sizeof(clsock));
                                    ^~~~~~
1 error generated.
make: *** [src/bind.o] Error 1

Error: Build error: Failed building.

I'm willing to retry with gcc, but how can I specify which compiler to use?

[gcr]

ah, i've been told that a fix for this is in master, sorry for the noise.