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

Run Build Command(s):/usr/bin/make cmTC_ebac7/fast && make[1]: Entering directory '/tmp/instance-1/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_ebac7.dir/build.make CMakeFiles/cmTC_ebac7.dir/build
make[2]: Entering directory '/tmp/instance-1/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_ebac7.dir/CheckFunctionExists.c.o
/tmp/instance-1/output-1/host/bin/arm-linux-gcc --sysroot=/tmp/instance-1/output-1/host/arm-buildroot-uclinux-uclibcgnueabi/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -Wl,-elf2flt -static -DCHECK_FUNCTION_EXISTS=dlopen  -DNDEBUG   -o CMakeFiles/cmTC_ebac7.dir/CheckFunctionExists.c.o   -c /usr/share/cmake-3.16/Modules/CheckFunctionExists.c
Linking C executable cmTC_ebac7
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_ebac7.dir/link.txt --verbose=1
/tmp/instance-1/output-1/host/bin/arm-linux-gcc --sysroot=/tmp/instance-1/output-1/host/arm-buildroot-uclinux-uclibcgnueabi/sysroot -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -Wl,-elf2flt -static -DCHECK_FUNCTION_EXISTS=dlopen  -DNDEBUG  -Wl,-elf2flt -static  CMakeFiles/cmTC_ebac7.dir/CheckFunctionExists.c.o  -o cmTC_ebac7  -ldl 
/tmp/instance-1/output-1/host/opt/ext-toolchain/arm-buildroot-uclinux-uclibcgnueabi/bin/ld.real: CMakeFiles/cmTC_ebac7.dir/CheckFunctionExists.c.o: in function `main':
CheckFunctionExists.c:(.text.startup+0x6): undefined reference to `dlopen'
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/cmTC_ebac7.dir/build.make:87: cmTC_ebac7] Error 1
make[2]: Leaving directory '/tmp/instance-1/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'
make[1]: *** [Makefile:121: cmTC_ebac7/fast] Error 2
make[1]: Leaving directory '/tmp/instance-1/output-1/build/libuhttpd-3.4.0/CMakeFiles/CMakeTmp'