build: ensure that libhostname doesn't get installed

tests/libtest/Makefile.am

@@ -53,19 +53,27 @@ endif
 EXTRA_DIST = test75.pl test307.pl test610.pl test613.pl test1013.pl	\
 test1022.pl Makefile.inc
 
-if STATICLIB
-# this means no shared option is enabled so we can disable the LD_PRELOAD
-# attempt
-libhostname_la_CFLAGS = -DDISABLE_PRELOAD
-endif
-
-# we force our own host name, in order to make some tests machine independent
-lib_LTLIBRARIES = libhostname.la
-libhostname_la_SOURCES = sethostname.c
-
 # Dependencies (may need to be overriden)
 LDADD = $(top_builddir)/lib/libcurl.la
 DEPENDENCIES = $(top_builddir)/lib/libcurl.la
 
-# Makefile.inc provides the source defines (TESTUTIL, SUPPORTFILES, noinst_PROGRAMS, lib*_SOURCES, and lib*_CFLAGS)
+# Makefile.inc provides the source defines (TESTUTIL, SUPPORTFILES,
+# noinst_PROGRAMS, lib*_SOURCES, and lib*_CFLAGS)
 include Makefile.inc
+
+# Preloading of libhostname allows host name overriding,
+# this is used to make some tests machine independent.
+
+noinst_LTLIBRARIES = libhostname.la
+
+if NO_UNDEFINED
+# The -no-undefined flag is crucial to build fine on some platforms
+UNDEF = -no-undefined
+endif
+
+libhostname_la_SOURCES = sethostname.c
+
+libhostname_la_LIBADD =
+libhostname_la_DEPENDENCIES =
+libhostname_la_LDFLAGS = -module -avoid-version $(UNDEF) -rpath /nowhere
+