For example:

	// #cgo pkg-config: png cairo
	// #include <png.h>
	import "C"

The default pkg-config tool may be changed by setting the PKG_CONFIG environment variable.

For security reasons, only a limited set of flags are allowed, notably -D, -U, -I, and -l.
To allow additional flags, set CGO_CFLAGS_ALLOW to a regular expression
matching the new flags. To disallow flags that would otherwise be allowed,

			Xattrs: map[string]string{
				"security.selinux": "unconfined_u:object_r:default_t:s0\x00",
			},
			PAXRecords: map[string]string{
				"mtime":                         "1386065770.449252304",
				"atime":                         "1389782991.41987522",
				"ctime":                         "1386065770.449252304",
				"SCHILY.xattr.security.selinux": "unconfined_u:object_r:default_t:s0\x00",
			},