Determining if the include file sys/iconv.h exists failed with the following output: Change Dir: /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp Run Build Command:"/gnu/store/vj24ah9a4kqsyhim2s4n6gvc4hsxhnli-make-4.2.1/bin/make" "cmTC_1da86/fast" /gnu/store/vj24ah9a4kqsyhim2s4n6gvc4hsxhnli-make-4.2.1/bin/make -f CMakeFiles/cmTC_1da86.dir/build.make CMakeFiles/cmTC_1da86.dir/build make[1]: Entering directory '/tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp' Building C object CMakeFiles/cmTC_1da86.dir/CheckIncludeFile.c.o /gnu/store/cfdn69spjc44x4sd0acrwhxq6yay3rbc-gcc-5.5.0/bin/gcc -I/gnu/store/n6acaivs0jwiwpidjr551dhdni5kgpcr-glibc-2.26.105-g0890d5379c/include -std=gnu99 -pedantic -pedantic-errors -Wall -Wextra -Wshadow -Wmissing-prototypes -Wunused -Wfloat-equal -Wpointer-arith -Wwrite-strings -Wformat-security -Wmissing-format-attribute -Wmissing-format-attribute -D_GNU_SOURCE -D__STDC_FORMAT_MACROS=1 -fPIC -fstack-protector -Wp,-D_FORTIFY_SOURCE=2 -D_LARGEFILE64_SOURCE -o CMakeFiles/cmTC_1da86.dir/CheckIncludeFile.c.o -c /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckIncludeFile.c /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckIncludeFile.c:1:23: fatal error: sys/iconv.h: No such file or directory compilation terminated. make[1]: *** [CMakeFiles/cmTC_1da86.dir/build.make:66: CMakeFiles/cmTC_1da86.dir/CheckIncludeFile.c.o] Error 1 make[1]: Leaving directory '/tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp' make: *** [Makefile:126: cmTC_1da86/fast] Error 2 Determining if the prototype iconv exists for HAVE_ICONV_CONST failed with the following output: Change Dir: /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp Run Build Command:"/gnu/store/vj24ah9a4kqsyhim2s4n6gvc4hsxhnli-make-4.2.1/bin/make" "cmTC_5b375/fast" /gnu/store/vj24ah9a4kqsyhim2s4n6gvc4hsxhnli-make-4.2.1/bin/make -f CMakeFiles/cmTC_5b375.dir/build.make CMakeFiles/cmTC_5b375.dir/build make[1]: Entering directory '/tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp' Building C object CMakeFiles/cmTC_5b375.dir/CheckPrototypeDefinition.c.o /gnu/store/cfdn69spjc44x4sd0acrwhxq6yay3rbc-gcc-5.5.0/bin/gcc -I/gnu/store/n6acaivs0jwiwpidjr551dhdni5kgpcr-glibc-2.26.105-g0890d5379c/include -std=gnu99 -pedantic -pedantic-errors -Wall -Wextra -Wshadow -Wmissing-prototypes -Wunused -Wfloat-equal -Wpointer-arith -Wwrite-strings -Wformat-security -Wmissing-format-attribute -Wmissing-format-attribute -D_GNU_SOURCE -D__STDC_FORMAT_MACROS=1 -fPIC -fstack-protector -Wp,-D_FORTIFY_SOURCE=2 -D_LARGEFILE64_SOURCE -o CMakeFiles/cmTC_5b375.dir/CheckPrototypeDefinition.c.o -c /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c In file included from /gnu/store/n6acaivs0jwiwpidjr551dhdni5kgpcr-glibc-2.26.105-g0890d5379c/include/iconv.h:21:0, from /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:1: /gnu/store/n6acaivs0jwiwpidjr551dhdni5kgpcr-glibc-2.26.105-g0890d5379c/include/features.h:376:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp] # warning _FORTIFY_SOURCE requires compiling with optimization (-O) ^ /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:14:8: 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 /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:1:0: /gnu/store/n6acaivs0jwiwpidjr551dhdni5kgpcr-glibc-2.26.105-g0890d5379c/include/iconv.h:42:15: note: previous declaration of ‘iconv’ was here extern size_t iconv (iconv_t __cd, char **__restrict __inbuf, ^ /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c: In function ‘iconv’: /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:14:22: warning: unused parameter ‘cd’ [-Wunused-parameter] size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) { ^ /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:14:39: warning: unused parameter ‘inbuf’ [-Wunused-parameter] size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) { ^ /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:14:54: warning: unused parameter ‘inbytesleft’ [-Wunused-parameter] size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) { ^ /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:14:74: warning: unused parameter ‘outbuf’ [-Wunused-parameter] size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) { ^ /tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp/CheckPrototypeDefinition.c:14:90: warning: unused parameter ‘outbytesleft’ [-Wunused-parameter] size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) { ^ make[1]: *** [CMakeFiles/cmTC_5b375.dir/build.make:66: CMakeFiles/cmTC_5b375.dir/CheckPrototypeDefinition.c.o] Error 1 make[1]: Leaving directory '/tmp/guix-build-owncloud-client-2.3.4.drv-0/build/CMakeFiles/CMakeTmp' make: *** [Makefile:126: cmTC_5b375/fast] Error 2 #include static void cmakeRequireSymbol(int dummy, ...) { (void) dummy; } static void checkSymbol(void) { #ifndef iconv cmakeRequireSymbol(0, &iconv); #endif } size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) { return -1; } #ifdef __CLASSIC_C__ int main() { int ac; char*av[]; #else int main(int ac, char *av[]) { #endif checkSymbol(); if (ac > 1000) { return *av[0]; } return 0; }