For compilation to work -D_GNU_SOURCE -Isrc/include is needed to be passed to the compiler. For Debian packaging several things are added but not these two from above. So be a bit more friendly and add them unconditionally. There is no harm if they are included in the user supplied CFLAGS and so passed twice. Moreover be a bit more correct about CFLAGS/CPPFLAGS. Both should be passed to the compiler with CFLAGS taking options for the compiler and CPPFLAGS taking options for the preprocessor. This is also needed for Debian packaging where the helper scripts set CPPFLAGS. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> --- Makefile | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Index: rt-tests/Makefile =================================================================== --- rt-tests.orig/Makefile 2012-09-02 22:04:06.547562496 +0200 +++ rt-tests/Makefile 2012-09-02 22:06:56.169496678 +0200 @@ -20,7 +20,8 @@ NUMA := 1 endif -CFLAGS ?= -D_GNU_SOURCE -Wall -Wno-nonnull -Isrc/include +CFLAGS ?= -Wall -Wno-nonnull +CPPFLAGS += -D_GNU_SOURCE -Isrc/include LDFLAGS ?= ifndef DEBUG @@ -47,7 +48,7 @@ VPATH += src/hackbench %.o: %.c - $(CC) -D VERSION_STRING=$(VERSION_STRING) -c $< $(CFLAGS) + $(CC) -D VERSION_STRING=$(VERSION_STRING) -c $< $(CFLAGS) $(CPPFLAGS) # Pattern rule to generate dependency files from .c files %.d: %.c -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html