title: gcc cannot find bits/predefs.h on i686
body: <p>Okay, so, I switched from ubuntu 12.04 64-bit to 32-bit and installed <code>build-essential.</code></p>
  
  <p>I then compiled and installed GMP-5.0.5, MPFR-3.1.1, MPC-1.0, ISL-0.10 and CLOOG-0.17.0. I checked out a copy of the main gcc trunk and attempted to build it with the following configure line (from a separate directory):</p>
  
  <pre><code>../svnsrc/configure --prefix=/usr/GCC/svn --enable-__cxa_atexit --with-plugin-ld=/usr/bin/ld.gold --enable-threads=posix --enable-werror --enable-build-with-cxx --with-gmp=/usr/GCC/prereq/svn --with-mpfr=/usr/GCC/prereq/svn --with-mpc=/usr/GCC/prereq/svn --with-isl=/usr/GCC/prereq/svn --with-cloog=/usr/GCC/prereq/svn --enable-languages=c,c++
  </code></pre>
  
  <p>Configure ran fine and so I ran <code>make &amp;&amp; make check</code>. This ran fine for a while, but then it failed with the following error:</p>
  
  <pre><code>/home/matt/GCC/svnbuild/./gcc/xgcc -B/home/matt/GCC/svnbuild/./gcc/ -B/usr/GCC/svn/i686-pc-linux-gnu/bin/ -B/usr/GCC/svn/i686-pc-linux-gnu/lib/ -isystem /usr/GCC/svn/i686-pc-linux-gnu/include -isystem /usr/GCC/svn/i686-pc-linux-gnu/sys-include    -g -O2 -O2  -g -O2 -DIN_GCC   -W -Wall -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition  -isystem ./include   -fpic -mlong-double-80 -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector   -fpic -mlong-double-80 -I. -I. -I../.././gcc -I../../../svnsrc/libgcc -I../../../svnsrc/libgcc/. -I../../../svnsrc/libgcc/../gcc -I../../../svnsrc/libgcc/../include -I../../../svnsrc/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS  -DUSE_TLS -o _muldi3.o -MT _muldi3.o -MD -MP -MF _muldi3.dep -DL_muldi3 -c ../../../svnsrc/libgcc/libgcc2.c -fvisibility=hidden -DHIDE_EXPORTS
  In file included from /usr/include/stdio.h:28:0,
                   from ../../../svnsrc/libgcc/../gcc/tsystem.h:88,
                   from ../../../svnsrc/libgcc/libgcc2.c:29:
  /usr/include/features.h:324:26: fatal error: bits/predefs.h: No such file or directory
   #include &lt;bits/predefs.h&gt;
                            ^
  compilation terminated.
  make[3]: *** [_muldi3.o] Error 1
  make[3]: Leaving directory `/home/matt/GCC/svnbuild/i686-pc-linux-gnu/libgcc
  </code></pre>
  
  <p>I looked around, but everything I seemed to find was that this error was caused on x86_64, by not installing <code>gcc-multilib</code>, because Ubuntu and Debian use the mutiarch system, separating the libraries. Okay, fine...but I'm using i686, so why would I need the 64-bit libraries? Any help would be appreciated. Thanks.</p>