$ clang --version
FreeBSD clang version 14.0.5 (https://github.com/llvm/llvm-project.git llvmorg-14.0.5-0-gc12386ae247c)
Target: x86_64-unknown-freebsd13.2
Thread model: posix
InstalledDir: /usr/bin

cc -DHAVE_CONFIG_H -I. -I../../src    -I./.. -I./../.. -I/usr/local/include -D_U_="__attribute__((unused))" -O2 -pipe  -fstack-protector-strong -fno-strict-aliasing   -Wno-variadic-macros -Wfatal-errors  -I/usr/lib -I/usr/include -MT libfragroute_a-fragroute.o -MD -MP -MF .deps/libfragroute_a-fragroute.Tpo -c -o libfragroute_a-fragroute.o `test -f 'fragroute.c' || echo './'`fragroute.c
mv -f .deps/libfragroute_a-fragroute.Tpo .deps/libfragroute_a-fragroute.Po
cc -DHAVE_CONFIG_H -I. -I../../src    -I./.. -I./../.. -I/usr/local/include -D_U_="__attribute__((unused))" -O2 -pipe  -fstack-protector-strong -fno-strict-aliasing   -Wno-variadic-macros -Wfatal-errors  -I/usr/lib -I/usr/include -MT libfragroute_a-bget.o -MD -MP -MF .deps/libfragroute_a-bget.Tpo -c -o libfragroute_a-bget.o `test -f 'bget.c' || echo './'`bget.c
mv -f .deps/libfragroute_a-bget.Tpo .deps/libfragroute_a-bget.Po
cc -DHAVE_CONFIG_H -I. -I../../src    -I./.. -I./../.. -I/usr/local/include -D_U_="__attribute__((unused))" -O2 -pipe  -fstack-protector-strong -fno-strict-aliasing   -Wno-variadic-macros -Wfatal-errors  -I/usr/lib -I/usr/include -MT libfragroute_a-mod.o -MD -MP -MF .deps/libfragroute_a-mod.Tpo -c -o libfragroute_a-mod.o `test -f 'mod.c' || echo './'`mod.c
mod.c:180:5: fatal error: incomplete definition of type 'struct next'
    TAILQ_FOREACH_REVERSE(rule, &rules, next, head)
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/sys/queue.h:750:15: note: expanded from macro 'TAILQ_FOREACH_REVERSE'
        for ((var) = TAILQ_LAST((head), headname);                      \
                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/sys/queue.h:824:44: note: expanded from macro 'TAILQ_LAST'
        (*(((struct headname *)((head)->tqh_last))->tqh_last))
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
mod.c:180:41: note: forward declaration of 'struct next'
    TAILQ_FOREACH_REVERSE(rule, &rules, next, head)
                                        ^