I sent this report just after a "rm -Rf * ; cmake ../" in my "build" directory.
The "cmake ../" raised no error on the console, I then ran "make".


Note : 
Strangely enough, I had the same error (Error: the swig import helper was not fixed...) some hours before, stopping the compilation circa 70%. I ran make again and the compilation gone throught the 70% but failed later with a GCC error (didn't saved it).



** Plateform Ubuntu 14.04 :

Description:    Ubuntu 14.04.5 LTS
Release:        14.04
Codename:       trusty


** The command swig -version gives : 

SWIG Version 4.0.0
Compiled with g++ [x86_64-unknown-linux-gnu]
Configured options: +pcre


** CMakefiles/CMakeError.log :

Performing C++ SOURCE FILE Test COMPILER_SUPPORTS_WSUGGEST_OVERRIDE failed with the following output:
Change Dir: /home/jeremy/kicad/kicad/build/CMakeFiles/CMakeTmp

Run Build Command:/usr/bin/make "cmTryCompileExec1021890506/fast"
/usr/bin/make -f CMakeFiles/cmTryCompileExec1021890506.dir/build.make CMakeFiles/cmTryCompileExec1021890506.dir/build
make[1]: Entering directory `/home/jeremy/kicad/kicad/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report /home/jeremy/kicad/kicad/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building CXX object CMakeFiles/cmTryCompileExec1021890506.dir/src.cxx.o
/usr/bin/c++    -fvisibility=hidden -fvisibility-inlines-hidden -std=c++11 -DCOMPILER_SUPPORTS_WSUGGEST_OVERRIDE -fPIE   -Wsuggest-override -o CMakeFiles/cmTryCompileExec1021890506.dir/src.cxx.o -c /home/jeremy/kicad/kicad/build/CMakeFiles/CMakeTmp/src.cxx
g++-4.8.real: error: unrecognized command line option '-Wsuggest-override'
make[1]: *** [CMakeFiles/cmTryCompileExec1021890506.dir/src.cxx.o] Error 1
make[1]: Leaving directory `/home/jeremy/kicad/kicad/build/CMakeFiles/CMakeTmp'
make: *** [cmTryCompileExec1021890506/fast] Error 2

Source file was:
int main() { return 0;}

** gcc -v gives : 
COLLECT_GCC=/usr/bin/gcc-4.8.real
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.4-2ubuntu1~14.04.4' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --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 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.4) 


I noobly didn't noticed the 

g++-4.8.real: error: unrecognized command line option '-Wsuggest-override'

in CMakeError.log...


Not sure about the relation between this error and my problem. I am going to solve this and run a fresh compilation again.