Determining if the NOTE_TRUNCATE exist failed with the following output: Change Dir: /home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp Run Build Command(s):/usr/bin/make -f Makefile cmTC_754df/fast && make[1]: Entering directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp' /usr/bin/make -f CMakeFiles/cmTC_754df.dir/build.make CMakeFiles/cmTC_754df.dir/build make[2]: Entering directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp' Building C object CMakeFiles/cmTC_754df.dir/CheckSymbolExists.c.o /home/buildroot/autobuild/run/instance-2/output-1/host/bin/xtensa-buildroot-linux-uclibc-gcc --sysroot=/home/buildroot/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 -g0 -DNDEBUG -fPIE -o CMakeFiles/cmTC_754df.dir/CheckSymbolExists.c.o -c /home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c /home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:2:10: fatal error: sys/event.h: No such file or directory 2 | #include | ^~~~~~~~~~~~~ compilation terminated. CMakeFiles/cmTC_754df.dir/build.make:77: recipe for target 'CMakeFiles/cmTC_754df.dir/CheckSymbolExists.c.o' failed make[2]: *** [CMakeFiles/cmTC_754df.dir/CheckSymbolExists.c.o] Error 1 make[2]: Leaving directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp' Makefile:127: recipe for target 'cmTC_754df/fast' failed make[1]: *** [cmTC_754df/fast] Error 2 make[1]: Leaving directory '/home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp' File /home/buildroot/autobuild/run/instance-2/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c: /* */ #include int main(int argc, char** argv) { (void)argv; #ifndef NOTE_TRUNCATE return ((int*)(&NOTE_TRUNCATE))[argc]; #else (void)argc; return 0; #endif }