extract below, this has already been reported a while back but still no new patch, so this email is to serve as a reminder, if someone manually fixes it for the ports tree, I dont consider that a fix, ideally we need this fixed in the source code, as not everyone will install it from ports.
Chris
"clang40 -DHAVE_CONFIG_H -I. -I../.. -I../../src/lib -I../../src/lib-dns -I../../src/lib-test -I../../src/lib-settings -I../../src/lib-ssl-iostream -DPKG_RUNDIR=\""/var/run/dovecot"\" -DPKG_STATEDIR=\""/var/lib/dovecot"\" -DSYSCONFDIR=\""/etc/dovecot"\" -DBINDIR=\""/usr/bin"\" -I/usr/local/include -std=gnu99 -fdiagnostics-color -Wl,-rpath=/usr/local/llvm40/lib -O2 -pipe -march=native -fno-strict-aliasing -fstack-protector-strong -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wall -W -Wmissing-prototypes -Wmissing-declarations -Wpointer-arith -Wchar-subscripts -Wformat=2 -Wbad-function-cast -Wno-duplicate-decl-specifier -Wstrict-aliasing=2 -I/usr/local/include -MT test-event-stats.o -MD -MP -MF .deps/test-event-stats.Tpo -c -o test-event-stats.o test-event-stats.c clang-4.0: warning: -Wl,-rpath=/usr/local/llvm40/lib: 'linker' input unused [-Wunused-command-line-argument] test-event-stats.c:101:8: warning: implicit declaration of function 'kill' is invalid in C99 [-Wimplicit-function-declaration] (void)kill(stats_pid, SIGKILL); ^ test-event-stats.c:101:24: error: use of undeclared identifier 'SIGKILL' (void)kill(stats_pid, SIGKILL); ^ 1 warning and 1 error generated. gmake[2]: *** [Makefile:656: test-event-stats.o] Error 1 gmake[2]: Leaving directory '/usr/local/directadmin/custombuild/dovecot-2.3.4/src/lib-master' gmake[1]: *** [Makefile:565: install-recursive] Error 1 gmake[1]: Leaving directory '/usr/local/directadmin/custombuild/dovecot-2.3.4/src' gmake: *** [Makefile:683: install-recursive] Error 1"