problem with oe-core sdk

~/$ cd opt/oecore-x86_64/
~/opt/oecore-x86_64/workspace$ source environment-setup-i586-oe-linux
~/opt/oecore-x86_64/workspace$ echo $CC
i586-oe-linux-gcc -m32 -march=i586 --sysroot=/home/christos/opt/oecore-x86_64/sysroots/i586-oe-linux
~/opt/oecore-x86_64/workspace$ which i586-oe-linux
~/opt/oecore-x86_64/workspace$ which i586-oe-linux-gcc/home/christos/opt/oecore-x86_64/sysroots/x86_64-oesdk-linux/usr/bin/i586-oe-linux/i586-oe-linux-gcc
~/opt/oecore-x86_64/workspace$ i586-oe-linux-gcc main.c
main.c:1:19: fatal error: stdio.h: No such file or directory
 #include <stdio.h>
                   ^
compilation terminated.