fail to build test on FreeBSD

[miniupnp]

$ uname -a
FreeBSD t420nnd.cls.to 10.3-RELEASE-p24 FreeBSD 10.3-RELEASE-p24 #0: Wed Nov 15 04:57:40 UTC 2017     root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64
$ gmake -C test
gmake : on entre dans le répertoire « /home/nanard/code/git/base64/test »
rm -f benchmark test_base64 *.o
cc -std=c99 -O3 -Wall -Wextra -pedantic -o codec_supported.o -c codec_supported.c
cc -std=c99 -O3 -Wall -Wextra -pedantic -o test_base64 test_base64.c codec_supported.o ../lib/libbase64.o
cc -std=c99 -O3 -Wall -Wextra -pedantic -o benchmark benchmark.c codec_supported.o ../lib/libbase64.o -lrt
benchmark.c:101:16: error: use of undeclared identifier 'CLOCK_REALTIME'
        clock_gettime(CLOCK_REALTIME, o_time);
                      ^
benchmark.c:99:35: warning: unused parameter 'o_time' [-Wunused-parameter]
base64_gettime (base64_timespec * o_time)
                                  ^
1 warning and 1 error generated.
gmake: *** [Makefile:24: benchmark] Error 1

Adding -D_XOPEN_SOURCE=600 does the trick

diff --git a/test/Makefile b/test/Makefile
index d104582..11c57a3 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -2,6 +2,7 @@ CFLAGS += -std=c99 -O3 -Wall -Wextra -pedantic
 ifdef OPENMP
   CFLAGS += -fopenmp
 endif
+CFLAGS += -D_XOPEN_SOURCE=600

 TARGET := $(shell $(CC) -dumpmachine)
 ifneq (, $(findstring darwin, $(TARGET)))

[aklomp]

Merged, finally. Sorry for the delay, I had moved on to other projects for a while. Thanks for the report!