Hello The sizeof hook calculates the size wrong in this example: ----------------------------------------------------------------- main = putStrLn (show {# sizeof loop_info64_t #}) #c #include typedef struct loop_info64 loop_info64_t; #endc ----------------------------------------------------------------- Translated to: ----------------------------------------------------------------- ... {-# LINE 1 "bug.chs" #-}main = putStrLn (show 72) ----------------------------------------------------------------- The structure is much larger. loop_info64 is defined in /usr/include/linux/loop.h like this: ----------------------------------------------------------------- struct loop_info64 { __u64 lo_device; /* ioctl r/o */ __u64 lo_inode; /* ioctl r/o */ __u64 lo_rdevice; /* ioctl r/o */ __u64 lo_offset; __u64 lo_sizelimit;/* bytes, 0 == max available */ __u32 lo_number; /* ioctl r/o */ __u32 lo_encrypt_type; __u32 lo_encrypt_key_size; /* ioctl w/o */ __u32 lo_flags; /* ioctl r/o */ __u8 lo_file_name[LO_NAME_SIZE]; __u8 lo_crypt_name[LO_NAME_SIZE]; __u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ __u64 lo_init[2]; }; ----------------------------------------------------------------- It looks like the the arrays are mistaken for pointers. There's another small bug. If you reorder main and the C block in the example above, such that "#c" is the first line, then you get a parse error. -- public key fingerprint: 6A10 66F1 40A2 C441 BB55 0AA8 FAB1 4FC1 08BE 24EF