Fix macos build

Author: wz1000

.gitlab/ci.sh

@@ -36,6 +36,7 @@ case "$(uname -s)" in
 		case "$(/usr/bin/arch)" in
 			aarch64|arm64|armv8l)
 				curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | arch -arm64 /bin/bash
+				export C_INCLUDE_PATH="`xcrun --show-sdk-path`/usr/include/ffi"
 				;;
 			*)
 				curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh