title: C compiler cannot create executables in Ubuntu 12.04
body: <p>I'm trying to configure cpuminer for litecoins and I get </p>
  
  <pre><code>checking whether the C compiler works... no
  configure: error: in `/home/username/cpuminer-2.2.3':
  configure: error: C compiler cannot create executables
  See `config.log' for more details
  </code></pre>
  
  <p>This is on Ubuntu 12.04 x64.</p>
  
  <p>I am not sure what can be happening, but I have run updates and I have gcc installed. I read a number of articles, but they seem to be pointing to different things.</p>
  
  <p>The output of the config.log is</p>
  
  <pre><code>This file contains any messages produced by compilers while
  running configure, to aid debugging if configure makes a mistake.
  
  It was created by cpuminer configure 2.2.3, which was
  generated by GNU Autoconf 2.68.  Invocation command line was
  
    $ ./configure CFLAGS=-03
  
  ## --------- ##
  ## Platform. ##
  ## --------- ##
  
  hostname = comanche
  uname -m = x86_64
  uname -r = 3.5.0-27-generic
  uname -s = Linux
  uname -v = #46-Ubuntu SMP Mon Mar 25 19:58:17 UTC 2013
  
  /usr/bin/uname -p = unknown
  /bin/uname -X     = unknown
  
  /bin/arch              = unknown
  /usr/bin/arch -k       = unknown
  /usr/convex/getsysinfo = unknown
  /usr/bin/hostinfo      = unknown
  /bin/machine           = unknown
  /usr/bin/oslevel       = unknown
  /bin/universe          = unknown
  
  PATH: /usr/local/sbin
  PATH: /usr/local/bin
  PATH: /usr/sbin
  PATH: /usr/bin
  PATH: /sbin
  PATH: /bin
  
  
  ## ----------- ##
  ## Core tests. ##
  ## ----------- ##
  
  configure:2300: checking build system type
  configure:2314: result: x86_64-unknown-linux-gnu
  configure:2334: checking host system type
  configure:2347: result: x86_64-unknown-linux-gnu
  configure:2367: checking target system type
  configure:2380: result: x86_64-unknown-linux-gnu
  configure:2424: checking for a BSD-compatible install
  configure:2492: result: /usr/bin/install -c
  configure:2503: checking whether build environment is sane
  configure:2553: result: yes
  configure:2694: checking for a thread-safe mkdir -p
  configure:2733: result: /bin/mkdir -p
  configure:2746: checking for gawk
  configure:2776: result: no
  configure:2746: checking for mawk
  configure:2762: found /usr/bin/mawk
  configure:2773: result: mawk
  configure:2784: checking whether make sets $(MAKE)
  configure:2806: result: yes
  configure:2890: checking whether to enable maintainer-specific portions of Makefiles
  configure:2899: result: no
  configure:2925: checking for style of include used by make
  configure:2953: result: GNU
  configure:3024: checking for gcc
  configure:3040: found /usr/bin/gcc
  configure:3051: result: gcc
  configure:3280: checking for C compiler version
  configure:3289: gcc --version &gt;&amp;5
  gcc (Ubuntu/Linaro 4.7.2-2ubuntu1) 4.7.2
  Copyright (C) 2012 Free Software Foundation, Inc.
  This is free software; see the source for copying conditions.  There is NO
  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  
  configure:3300: $? = 0
  configure:3289: gcc -v &gt;&amp;5
  Using built-in specs.
  COLLECT_GCC=gcc
  COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
  Target: x86_64-linux-gnu
  Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.2-2ubuntu1' --    with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-    languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared     --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext     --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --    enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-    libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-    werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-    linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
  Thread model: posix
  gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1) 
  configure:3300: $? = 0
  configure:3289: gcc -V &gt;&amp;5
  gcc: error: unrecognized command line option '-V'
  gcc: fatal error: no input files
  compilation terminated.
  configure:3300: $? = 4
  configure:3289: gcc -qversion &gt;&amp;5
  gcc: error: unrecognized command line option '-qversion'
  gcc: fatal error: no input files
  compilation terminated.
  configure:3300: $? = 4
  configure:3320: checking whether the C compiler works
  configure:3342: gcc -03   conftest.c  &gt;&amp;5
  gcc: error: unrecognized command line option '-03'
  configure:3346: $? = 1
  configure:3384: result: no
  configure: failed program was:
  | /* confdefs.h */
  | #define PACKAGE_NAME "cpuminer"
  | #define PACKAGE_TARNAME "cpuminer"
  | #define PACKAGE_VERSION "2.2.3"
  | #define PACKAGE_STRING "cpuminer 2.2.3"
  | #define PACKAGE_BUGREPORT ""
  | #define PACKAGE_URL ""
  | #define PACKAGE "cpuminer"
  | #define VERSION "2.2.3"
  | /* end confdefs.h.  */
  | 
  | int
  | main ()
  | {
  | 
  |   ;
  |   return 0;
  | }
  configure:3389: error: in `/home/username/cpuminer-2.2.3':
  configure:3391: error: C compiler cannot create executables
  See `config.log' for more details
  
  ## ---------------- ##
  ## Cache variables. ##
  ## ---------------- ##
  
  ac_cv_build=x86_64-unknown-linux-gnu
  ac_cv_env_CCASFLAGS_set=
  ac_cv_env_CCASFLAGS_value=
  ac_cv_env_CCAS_set=
  ac_cv_env_CCAS_value=
  ac_cv_env_CC_set=
  ac_cv_env_CC_value=
  ac_cv_env_CFLAGS_set=set
  ac_cv_env_CFLAGS_value=-03
  ac_cv_env_CPPFLAGS_set=
  ac_cv_env_CPPFLAGS_value=
  ac_cv_env_CPP_set=
  ac_cv_env_CPP_value=
  ac_cv_env_LDFLAGS_set=
  ac_cv_env_LDFLAGS_value=
  ac_cv_env_LIBS_set=
  ac_cv_env_LIBS_value=
  ac_cv_env_build_alias_set=
  ac_cv_env_build_alias_value=
  ac_cv_env_host_alias_set=
  ac_cv_env_host_alias_value=
  ac_cv_env_target_alias_set=
  ac_cv_env_target_alias_value=
  ac_cv_host=x86_64-unknown-linux-gnu
  ac_cv_path_install='/usr/bin/install -c'
  ac_cv_path_mkdir=/bin/mkdir
  ac_cv_prog_AWK=mawk
  ac_cv_prog_ac_ct_CC=gcc
  ac_cv_prog_make_make_set=yes
  ac_cv_target=x86_64-unknown-linux-gnu
  
  ## ----------------- ##
  ## Output variables. ##
  ## ----------------- ##
  
  ACLOCAL='${SHELL} /home/username/cpuminer-2.2.3/missing --run aclocal-1.11'
  ALLOCA=''
  AMDEPBACKSLASH='\'
  AMDEP_FALSE='#'
  AMDEP_TRUE=''
  AMTAR='$${TAR-tar}'
  ARCH_x86_64_FALSE=''
  ARCH_x86_64_TRUE=''
  ARCH_x86_FALSE=''
  ARCH_x86_TRUE=''
  AUTOCONF='${SHELL} /home/username/cpuminer-2.2.3/missing --run autoconf'
  AUTOHEADER='${SHELL} /home/username/cpuminer-2.2.3/missing --run autoheader'
  AUTOMAKE='${SHELL} /home/username/cpuminer-2.2.3/missing --run automake-1.11'
  AWK='mawk'
  CC='gcc'
  CCAS=''
  CCASDEPMODE=''
  CCASFLAGS=''
  CCDEPMODE=''
  CFLAGS='-03'
  CPP=''
  CPPFLAGS=''
  CYGPATH_W='echo'
  DEFS=''
  DEPDIR='.deps'
  ECHO_C=''
  ECHO_N='-n'
  ECHO_T=''
  EGREP=''
  EXEEXT=''
  GREP=''
  HAVE_WINDOWS_FALSE=''
  HAVE_WINDOWS_TRUE=''
  INSTALL_DATA='${INSTALL} -m 644'
  INSTALL_PROGRAM='${INSTALL}'
  INSTALL_SCRIPT='${INSTALL}'
  INSTALL_STRIP_PROGRAM='$(install_sh) -c -s'
  JANSSON_LIBS=''
  LDFLAGS=''
  LIBCURL=''
  LIBCURL_CPPFLAGS=''
  LIBOBJS=''
  LIBS=''
  LTLIBOBJS=''
  MAINT='#'
  MAINTAINER_MODE_FALSE=''
  MAINTAINER_MODE_TRUE='#'
  MAKEINFO='${SHELL} /home/username/cpuminer-2.2.3/missing --run makeinfo'
  MKDIR_P='/bin/mkdir -p'
  OBJEXT=''
  PACKAGE='cpuminer'
  PACKAGE_BUGREPORT=''
  PACKAGE_NAME='cpuminer'
  PACKAGE_STRING='cpuminer 2.2.3'
  PACKAGE_TARNAME='cpuminer'
  PACKAGE_URL=''
  PACKAGE_VERSION='2.2.3'
  PATH_SEPARATOR=':'
  PTHREAD_FLAGS=''
  PTHREAD_LIBS=''
  RANLIB=''
  SET_MAKE=''
  SHELL='/bin/bash'
  STRIP=''
  VERSION='2.2.3'
  WANT_JANSSON_FALSE=''
  WANT_JANSSON_TRUE=''
  WS2_LIBS=''
  _libcurl_config=''
  ac_ct_CC='gcc'
  am__EXEEXT_FALSE=''
  am__EXEEXT_TRUE=''
  am__fastdepCCAS_FALSE=''
  am__fastdepCCAS_TRUE=''
  am__fastdepCC_FALSE=''
  am__fastdepCC_TRUE=''
  am__include='include'
  am__isrc=''
  am__leading_dot='.'
  am__nodep='_no'
  am__quote=''
  am__tar='$${TAR-tar} chof - "$$tardir"'
  am__untar='$${TAR-tar} xf -'
  bindir='${exec_prefix}/bin'
  build='x86_64-unknown-linux-gnu'
  build_alias=''
  build_cpu='x86_64'
  build_os='linux-gnu'
  build_vendor='unknown'
  datadir='${datarootdir}'
  datarootdir='${prefix}/share'
  docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
  dvidir='${docdir}'
  exec_prefix='NONE'
  host='x86_64-unknown-linux-gnu'
  host_alias=''
  host_cpu='x86_64'
  host_os='linux-gnu'
  host_vendor='unknown'
  htmldir='${docdir}'
  includedir='${prefix}/include'
  infodir='${datarootdir}/info'
  install_sh='${SHELL} /home/username/cpuminer-2.2.3/install-sh'
  libdir='${exec_prefix}/lib'
  libexecdir='${exec_prefix}/libexec'
  localedir='${datarootdir}/locale'
  localstatedir='${prefix}/var'
  mandir='${datarootdir}/man'
  mkdir_p='/bin/mkdir -p'
  oldincludedir='/usr/include'
  pdfdir='${docdir}'
  prefix='NONE'
  program_transform_name='s,x,x,'
  psdir='${docdir}'
  sbindir='${exec_prefix}/sbin'
  sharedstatedir='${prefix}/com'
  sysconfdir='${prefix}/etc'
  target='x86_64-unknown-linux-gnu'
  target_alias=''
  target_cpu='x86_64'
  target_os='linux-gnu'
  target_vendor='unknown'
  
  ## ----------- ##
  ## confdefs.h. ##
  ## ----------- ##
  
  /* confdefs.h */
  #define PACKAGE_NAME "cpuminer"
  #define PACKAGE_TARNAME "cpuminer"
  #define PACKAGE_VERSION "2.2.3"
  #define PACKAGE_STRING "cpuminer 2.2.3"
  #define PACKAGE_BUGREPORT ""
  #define PACKAGE_URL ""
  #define PACKAGE "cpuminer"
  #define VERSION "2.2.3"
  
  configure: exit 77
  </code></pre>