Cygwin supports <dlfcn.h> and even has limited LD_PRELOAD capabilities; but because it does not use ELF binaries it cannot support RTLD_NEXT lookups. CC libvirportallocatormock_la-virportallocatortest.lo virportallocatortest.c: In function 'init_syms': virportallocatortest.c:47:24: error: 'RTLD_NEXT' undeclared (first use in this function) realsocket = dlsym(RTLD_NEXT, "socket"); * tests/virportallocatortest.c: Also require RTLD_NEXT. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- Pushing under the build-breaker rule. tests/virportallocatortest.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tests/virportallocatortest.c b/tests/virportallocatortest.c index 34843e3..5a93dad 100644 --- a/tests/virportallocatortest.c +++ b/tests/virportallocatortest.c @@ -23,7 +23,7 @@ #include "virfile.h" #include "testutils.h" -#if HAVE_DLFCN_H +#if HAVE_DLFCN_H && defined(RTLD_NEXT) # ifdef MOCK_HELPER # include "internal.h" -- 1.8.5.3