Userspace RCU

I am trying to configure lttng-tools against a master userspace-rcu (5510757134071e2bb6b554e7d0aaf29676150065) with -Wall -Werror. lttng-tools' configure script checks for the futex_async functions using this snippet:

504 AC_CHECK_DECL([futex_async], [],
505         [AC_MSG_ERROR([WRONG_LIBURCU_MSG])], [[#include <urcu/futex.h>]])

resulting in:

12141 configure:21855: checking whether futex_async is declared
12142 configure:21855: ccache gcc -c -g3 -O0 -Werror -fmax-errors=1 -fdiagnostics-color=always -fsanitize=address -Wall -I/tmp/userspace-rcu/include  conftest.c >&5
12143 In file included from ^[[01m^[[Kconftest.c:171:0^[[m^[[K:
12144 ^[[01m^[[K/tmp/userspace-rcu/include/urcu/futex.h:51:16:^[[m^[[K ^[[01;31m^[[Kerror: ^[[m^[[K'^[[01m^[[Kstruct timespec^[[m^[[K' declared inside parameter list will not be visible outside of this definition or declaration [^[      [01;31m^[[K-Werror^[[m^[[K]
12145    const struct ^[[01;31m^[[Ktimespec^[[m^[[K *timeout, int32_t *uaddr2, int32_t val3);
12146                 ^[[01;31m^[[K^~~~~~~~^[[m^[[K
12147 compilation terminated due to -fmax-errors=1.
12148 configure:21855: $? = 1

If futex.h uses struct timespec, I think it should include time.h.