Using `-isystem /usr/include` causes compile time errors with GCC 7
This is related to issue 48 but probably not directly to FFTW. I use OpenSuSE 15.4 and the current master branch. The configuration adds -isystem /usr/include
to many flags.make file and the result is the same error message es referenced in issue 48.
The workaround is to execute
find . -name "*flags*" -exec sed -ibak -e 's/-isystem \/usr\/include$/ /g' {} \;
and/or
find . -name "*flags*" -exec sed -ibak -e 's/-isystem \/usr\/include / /g' {} \;
For example, ./library/Collections/CMakeFiles/Collections.dir/flags.make
:
# CMAKE generated file: DO NOT EDIT!
# Generated by "Unix Makefiles" Generator, CMake Version 3.20
# compile CXX with /usr/lib/hpc/compiler/gnu/7/bin/c++
CXX_DEFINES = -DCollections_EXPORTS -DNEKTAR_MEMORY_POOL_ENABLED -DNEKTAR_USE_SCOTCH -DNEKTAR_USING_VTK -DNEKTAR_VERSION=\"5.3.0\" -DTIXML_USE_STL
CXX_INCLUDES = -I/home/lada/f/nektar-build-serial/ThirdParty/dist/include -I/home/lada/f/nektar++/library -I/home/lada/f/nektar++/utilities -I/home/lada/f/nektar++/solvers -isystem /usr/lib/hpc/gnu7/openmpi2/ptscotch/6.1.0/include -isystem /usr/include
CXX_FLAGS = -O3 -DNDEBUG -DNEKTAR_RELEASE -fPIC -fPIC -Wall -Wextra -Wpedantic -Wnon-virtual-dtor -Wno-sign-compare -Wno-narrowing -Wno-conversion -std=c++14