Comment 1:

Had a quick look;
struct timespec {
        time_t  tv_sec;         /* seconds */
        long    tv_nsec;        /* and nanoseconds */
};
1. run go tool cgo -godefs openbsd.go and got;
// Created by cgo -godefs - DO NOT EDIT
// cgo -godefs openbsd.go
package syscall
type Timespec struct {
        Rmx_expire      int32
        Pad_cgo_0       [4]byte
        Tv_nsec int64
}
2. When we remove "#include <net/bpf.h>" line from openbsd.go, got;
// Created by cgo -godefs - DO NOT EDIT
// cgo -godefs openbsd.go
package syscall
type Timespec struct {
        Sec     int32
        Pad_cgo_0       [4]byte
        Nsec    int64
}
Funny. Perhaps we should have a look at debug/elf package.
% uname -a
OpenBSD vm.localhost 5.2 GENERIC.MP #10 amd64
% hg id
9b31d3f52fff+ tip

Attachments:

1. openbsd.go (1056 bytes)
2. cgo-godefs-debug-gcc.txt (113793 bytes)

Comment 2:

P.S. Original motivation to generate z-files on OpenBSD is,
just needed for Go 1.1 because OpenBSD 5.1? .2 changed their 
ABI especially if_data in net/if.h and that breaks net.Interfaces API.

Comment 4:

Status changed to Duplicate.

Merged into issue #4107.