Determining if the NOTE_TRUNCATE exist failed with the following output:
Change Dir: /home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/gmake -f Makefile cmTC_dc2b4/fast && gmake[1]: Entering directory '/home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp'
/usr/bin/gmake  -f CMakeFiles/cmTC_dc2b4.dir/build.make CMakeFiles/cmTC_dc2b4.dir/build
gmake[2]: Entering directory '/home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_dc2b4.dir/CheckSymbolExists.c.o
/home/buildroot/instance-0/output-1/host/bin/m68k-linux-gcc --sysroot=/home/buildroot/instance-0/output-1/host/m68k-buildroot-linux-uclibc/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2   -DNDEBUG -fPIE -o CMakeFiles/cmTC_dc2b4.dir/CheckSymbolExists.c.o -c /home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c
/home/buildroot/instance-0/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 <sys/event.h>
      |          ^~~~~~~~~~~~~
compilation terminated.
gmake[2]: *** [CMakeFiles/cmTC_dc2b4.dir/build.make:78: CMakeFiles/cmTC_dc2b4.dir/CheckSymbolExists.c.o] Error 1
gmake[2]: Leaving directory '/home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp'
gmake[1]: *** [Makefile:127: cmTC_dc2b4/fast] Error 2
gmake[1]: Leaving directory '/home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp'


File /home/buildroot/instance-0/output-1/build/zeek-4.1.1/buildroot-build/libkqueue-build/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <sys/event.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef NOTE_TRUNCATE
  return ((int*)(&NOTE_TRUNCATE))[argc];
#else
  (void)argc;
  return 0;
#endif
}