Performing C SOURCE FILE Test ICONV_USES_CONST failed with the following output:
Change Dir: /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp

Run Build Command:/usr/bin/make "cmTryCompileExec1501071215/fast"
/usr/bin/make -f CMakeFiles/cmTryCompileExec1501071215.dir/build.make CMakeFiles/cmTryCompileExec1501071215.dir/build
make[1]: Entering directory `/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/CMakeFiles 1
Building C object CMakeFiles/cmTryCompileExec1501071215.dir/src.c.o
/usr/lib/ccache/cc   -DICONV_USES_CONST   -o CMakeFiles/cmTryCompileExec1501071215.dir/src.c.o   -c /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/src.c
/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/src.c:9:8: error: conflicting types for 'iconv'
 size_t iconv (iconv_t cd, const char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);
        ^
In file included from /var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp/src.c:3:0:
/usr/include/iconv.h:42:15: note: previous declaration of 'iconv' was here
 extern size_t iconv (iconv_t __cd, char **__restrict __inbuf,
               ^
make[1]: Leaving directory `/var/uhubuild/work/compile/build/CMakeFiles/CMakeTmp'
make[1]: *** [CMakeFiles/cmTryCompileExec1501071215.dir/src.c.o] Error 1
make: *** [cmTryCompileExec1501071215/fast] Error 2

Source file was:

#include <stdlib.h>
#include <iconv.h>
extern
#ifdef __cplusplus
;C;
#endif
#if defined(__STDC__) || defined(__cplusplus)
size_t iconv (iconv_t cd, const char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);
#else
size_t iconv();
#endif

int main(void) { return 0; }