I had problem when compiling 32-bit ELF inside 64-bit Ubuntu. This is error message produced by GCC compiler :

cheap-laptop@my-machine:~/DEV-DIR$ gcc -m32 test.c -o test

In file included from /usr/include/stdio.h:27:0,

                 from test.c:1:

/usr/include/features.h:374:25: fatal error: sys/cdefs.h: No such file or directory

 #  include <sys/cdefs.h>

                         ^

compilation terminated.

I searched Google for this problem and found that libc6-dev-i386 must be installed first.

I installed it and had no luck, and same error still occurred. So I had Google again and found this link.

It suggested to remove purge libc6-dev and install it back using apt-get. Then, some message appeared and it look like this :-

cheap-laptop@my-machine:~/DEV-DIR$ sudo apt-get purge libc6-dev

Reading package lists... Done

Building dependency tree       

Reading state information... Done

The following packages were automatically installed and are no longer required:

  gir1.2-gee-0.8 gir1.2-gtk-2.0 icu-devtools libboost-atomic1.54.0

  libboost-chrono1.54.0 libboost-context1.54.0 libboost-filesystem1.54.0

  libboost-graph-parallel1.54.0 libboost-graph1.54.0 libboost-iostreams1.54.0

  libboost-locale1.54.0 libboost-log1.54.0 libboost-math1.54.0

  libboost-mpi-python1.54.0 libboost-mpi1.54.0 libboost-program-options1.54.0

  libboost-python1.54.0 libboost-random1.54.0 libboost-regex1.54.0

  libboost-serialization1.54.0 libboost-signals1.54.0 libboost-test1.54.0

  libboost-thread1.54.0 libboost-timer1.54.0 libboost-tools-dev

  libboost-wave1.54.0 libboost1.54-tools-dev libcairo-script-interpreter2

  libdbus-1-dev libgnutlsxx27 libgpg-error-dev libgssrpc4 libharfbuzz-dev

  libharfbuzz-gobject0 libibverbs-dev libice-dev libidn11-dev

  libkadm5clnt-mit9 libkadm5srv-mit9 libkdb5-7 libp11-kit-dev libpcrecpp0

  libpixman-1-dev libpthread-stubs0-dev libsm-dev libssl-doc libtasn1-6-dev

  libtinfo-dev libvala-0.22-0 libx11-dev libxau-dev libxcb-render0-dev

  libxcb-shm0-dev libxcb1-dev libxcomposite-dev libxcursor-dev libxdamage-dev

  libxdmcp-dev libxext-dev libxfixes-dev libxi-dev libxinerama-dev

  libxml2-utils libxrandr-dev libxrender-dev mpi-default-bin valac-0.22-vapi

  x11proto-composite-dev x11proto-randr-dev x11proto-render-dev

  x11proto-xinerama-dev

Use 'apt-get autoremove' to remove them.

The following packages will be REMOVED:

  comerr-dev* gcc-4.9-multilib* gcc-multilib* krb5-multidev* libatk1.0-dev*

  libboost-all-dev* libboost-atomic-dev* libboost-atomic1.54-dev*

  libboost-chrono-dev* libboost-chrono1.54-dev* libboost-context-dev*

  libboost-context1.54-dev* libboost-coroutine-dev*

  libboost-coroutine1.54-dev* libboost-date-time-dev*

  libboost-date-time1.54-dev* libboost-dev* libboost-exception-dev*

  libboost-exception1.54-dev* libboost-filesystem-dev*

  libboost-filesystem1.54-dev* libboost-graph-dev*

  libboost-graph-parallel-dev* libboost-graph-parallel1.54-dev*

  libboost-graph1.54-dev* libboost-iostreams-dev* libboost-iostreams1.54-dev*

  libboost-locale-dev* libboost-locale1.54-dev* libboost-log-dev*

  libboost-log1.54-dev* libboost-math-dev* libboost-math1.54-dev*

  libboost-mpi-dev* libboost-mpi-python-dev* libboost-mpi-python1.54-dev*

  libboost-mpi1.54-dev* libboost-program-options-dev*

  libboost-program-options1.54-dev* libboost-python-dev*

  libboost-python1.54-dev* libboost-random-dev* libboost-random1.54-dev*

  libboost-regex-dev* libboost-regex1.54-dev* libboost-serialization-dev*

  libboost-serialization1.54-dev* libboost-signals-dev*

  libboost-signals1.54-dev* libboost-system-dev* libboost-system1.54-dev*

  libboost-test-dev* libboost-test1.54-dev* libboost-thread-dev*

  libboost-thread1.54-dev* libboost-timer-dev* libboost-timer1.54-dev*

  libboost-wave-dev* libboost-wave1.54-dev* libboost1.54-dev* libc6-dev*

  libc6-dev-i386* libc6-dev-x32* libcairo2-dev* libcurl4-openssl-dev*

  libdbus-glib-1-dev* libdbusmenu-glib-dev* libdee-dev* libexpat1-dev*

  libfontconfig1-dev* libfreetype6-dev* libgcrypt11-dev* libgdk-pixbuf2.0-dev*

  libgee-0.8-dev* libglib2.0-dev* libgnutls-dev* libgpgme11-dev*

  libgtk2.0-dev* libhwloc-dev* libicu-dev* libkrb5-dev* libncurses5-dev*

  libncursesw5-dev* libnotify-dev* libopenmpi-dev* libpango1.0-dev*

  libpcap-dev* libpcap0.8-dev* libpci-dev* libpcre3-dev* libpng12-dev*

  libpython-dev* libpython2.7-dev* librtmp-dev* libsqlite3-dev* libssh-dev*

  libssh2-1-dev* libssl-dev* libstdc++-4.8-dev* libunity-dev* libxft-dev*

  mpi-default-dev* nvidia-331* python2.7-dev* uuid-dev* valac-0.22*

  zlib1g-dev*

0 upgraded, 0 newly installed, 107 to remove and 0 not upgraded.

After this operation, 506 MB disk space will be freed.

Do you want to continue? [Y/n] 

It want to remove important packages such as libboost-*, nvidia-331* and others. Why this is happening?