make[4]: Entering directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
make[5]: Entering directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
make[6]: Entering directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
make[6]: Leaving directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
make[6]: Entering directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
[  0%] Building CXX object src/error/CMakeFiles/elektra-export-errors.dir/exporterrors.cpp.o
exporterrors.cpp: In function 'int main(int, char**)':
exporterrors.cpp:389:34: error: 'to_string' was not declared in this scope
   tmpfile += to_string (getpid ());
                                  ^
src/error/CMakeFiles/elektra-export-errors.dir/build.make:62: recipe for target 'src/error/CMakeFiles/elektra-export-errors.dir/exporterrors.cpp.o' failed
make[6]: *** [src/error/CMakeFiles/elektra-export-errors.dir/exporterrors.cpp.o] Error 1
make[6]: Leaving directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
CMakeFiles/Makefile2:244: recipe for target 'src/error/CMakeFiles/elektra-export-errors.dir/all' failed
make[5]: *** [src/error/CMakeFiles/elektra-export-errors.dir/all] Error 2
make[5]: Leaving directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
Makefile:160: recipe for target 'all' failed
make[4]: *** [all] Error 2
make[4]: Leaving directory '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19'
Makefile:395: recipe for target '/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19/.built' failed
make[3]: *** [/build/lede-17.01/slaves/phase2/arc_archs/build/sdk/build_dir/target-arc_archs_uClibc-1.0.14/elektra-0.8.19/.built] Error 2