failed to build 0.6.1 in Ubuntu

[PandaJim]

Hi, just tried to build Supertux 0.6.1 in Ubuntu 18.04 but got following error. Anyone help?

Performing C++ SOURCE FILE Test HAVE_ICONV_CONST failed with the following output:
Change Dir: /<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_f461a/fast"
make[2]: Entering directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_f461a.dir/build.make CMakeFiles/cmTC_f461a.dir/build
make[3]: Entering directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_f461a.dir/src.cxx.o
/usr/bin/c++    -g -O2 -fdebug-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -DHAVE_ICONV_CONST   -o CMakeFiles/cmTC_f461a.dir/src.cxx.o -c /<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp/src.cxx
/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp/src.cxx:4:9: error: ambiguating new declaration of ‘double iconv(iconv_t, char**, size_t*, char**, size_t*)’
  double iconv(iconv_t cd,  char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
         ^~~~~
In file included from /<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp/src.cxx:2:
/usr/include/iconv.h:42:15: note: old declaration ‘size_t iconv(iconv_t, char**, size_t*, char**, size_t*)’
 extern size_t iconv (iconv_t __cd, char **__restrict __inbuf,
               ^~~~~
make[3]: *** [CMakeFiles/cmTC_f461a.dir/build.make:66: CMakeFiles/cmTC_f461a.dir/src.cxx.o] Error 1
make[3]: Leaving directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp'
make[2]: *** [Makefile:121: cmTC_f461a/fast] Error 2
make[2]: Leaving directory '/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp'

Source file was:

	#include <iconv.h>
	// this declaration will fail when there already exists a non const char** version which returns size_t
	double iconv(iconv_t cd,  char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
	int main() { return 0; }
	

[tobbi]

This check should not cause the build to fail from what I can tell. Can you check whether it compiles nonetheless or give me a complete build output?