Go 1.8 plugins, fatal error: stddef.h: No such file - c

Question

Observe:
$ cat /tmp/plugin.go
package main
import "fmt"
var V int
func F() { fmt.Printf("Hello, number %d\n", V) }
$ go build -buildmode=plugin -o /tmp/plugin.so /tmp/plugin.go
# runtime/cgo
cgo-builtin-prolog:1:57: fatal error: stddef.h: No such file or directory
compilation terminated.
Why is that?
This is under Ubuntu 17.04, and I have build-essentials installed:
$ go version
go version go1.9 linux/amd64
$ uname -r
4.10.0-37-generic
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 17.04
Release: 17.04
Codename: zesty
$ apt-cache policy build-essential
build-essential:
Installed: 12.1ubuntu2
Candidate: 12.1ubuntu2
please not the "Compilation error: "stddef.h: No such file or directory"" is NOT the answer as my gcc-core package and gcc-g++ are of the same version -- here are my gcc related packages:
gcc_4:6.3.0-2ubuntu1
gcc-6_6.3.0-12ubuntu2
gcc-6-base:amd64_6.3.0-12ubuntu2
libgcc-6-dev:amd64_6.3.0-12ubuntu2
libgcc1:amd64_1:6.3.0-12ubuntu2
UPDATE:
thanks #peterSO, seems to be my gcc's own problem:
$ cat /tmp/foo.c
#include <stdio.h>
$ gcc /tmp/foo.c
In file included from /tmp/foo.c:1:0:
/usr/include/stdio.h:33:21: fatal error: stddef.h: No such file or directory
# include <stddef.h>
While searching for solution for it, I found someone suggested to reinstall gcc, so I did, together with libc6-dev:
apt-get --reinstall install libgcc-6-dev gcc-6 gcc-6-base:amd64 libc6-dev:amd64
Now my simple .c file compiles OK now, but I'm bumped into a new problem with cgo:
$ go build -buildmode=plugin -o /tmp/plugin.so /tmp/plugin.go
# runtime/cgo
In file included from /usr/include/errno.h:35:0,
from cgo-gcc-prolog:21:
/usr/include/x86_64-linux-gnu/bits/errno.h:24:26: fatal error: linux/errno.h: No such file or directory
# include <linux/errno.h>
^
compilation terminated.
I know this might be a Ubuntu/gcc specific problem (Ref: Why is stddef.h not in /usr/include? and my stddef.h is under /usr/src/linux-headers-4.10.0-37/include/linux/stddef.h), but anybody here knows Go and gcc good enough to know how to fix it, so that Go plugins can be compiled properly?
Thx!