Determining if the function dlopen exists in the dl failed with the following output:
Change Dir: /srv/storage/autobuild/run/instance-2/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp

Run Build Command:"/usr/bin/make" "cmTC_f0d86/fast"
make[1]: Entering directory '/srv/storage/autobuild/run/instance-2/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_f0d86.dir/build.make CMakeFiles/cmTC_f0d86.dir/build
make[2]: Entering directory '/srv/storage/autobuild/run/instance-2/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_f0d86.dir/CheckFunctionExists.c.o
/srv/storage/autobuild/run/instance-2/output-1/host/bin/xtensa-buildroot-linux-uclibc-gcc --sysroot=/srv/storage/autobuild/run/instance-2/output-1/host/xtensa-buildroot-linux-uclibc/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -mlongcalls -mauto-litpools -Os -static -DCHECK_FUNCTION_EXISTS=dlopen  -DNDEBUG   -o CMakeFiles/cmTC_f0d86.dir/CheckFunctionExists.c.o   -c /usr/share/cmake-3.13/Modules/CheckFunctionExists.c
Linking C executable cmTC_f0d86
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_f0d86.dir/link.txt --verbose=1
/srv/storage/autobuild/run/instance-2/output-1/host/bin/xtensa-buildroot-linux-uclibc-gcc --sysroot=/srv/storage/autobuild/run/instance-2/output-1/host/xtensa-buildroot-linux-uclibc/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -mlongcalls -mauto-litpools -Os -static -DCHECK_FUNCTION_EXISTS=dlopen  -DNDEBUG  -static  CMakeFiles/cmTC_f0d86.dir/CheckFunctionExists.c.o  -o cmTC_f0d86 -ldl 
/srv/storage/autobuild/run/instance-2/output-1/host/lib/gcc/xtensa-buildroot-linux-uclibc/9.3.0/../../../../xtensa-buildroot-linux-uclibc/bin/ld: CMakeFiles/cmTC_f0d86.dir/CheckFunctionExists.c.o:(.text.startup+0x0): undefined reference to `dlopen'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_f0d86.dir/build.make:87: cmTC_f0d86] Error 1
make[2]: Leaving directory '/srv/storage/autobuild/run/instance-2/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_f0d86/fast] Error 2
make[1]: Leaving directory '/srv/storage/autobuild/run/instance-2/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'