Preparing to unpack .../libc6-i386_2.21-0ubuntu4_amd64.deb ...
Unpacking libc6-i386 (2.21-0ubuntu4) ...
Replaced by files in installed package libc6:i386 (2.21-0ubuntu4) ...
Selecting previously unselected package libc6-dev-i386.
Preparing to unpack .../libc6-dev-i386_2.21-0ubuntu4_amd64.deb ...
Unpacking libc6-dev-i386 (2.21-0ubuntu4) ...
dpkg: error processing archive /var/cache/apt/archives/libc6-dev-i386_2.21-0ubuntu4_amd64.deb (--unpack):
 trying to overwrite '/usr/include/fpu_control.h', which is also in package libc6-dev-amd64:i386 2.21-0ubuntu4