Specify output explicitly for the .c.o compile rule

newlib/libc/Makefile.am

 ## Process this file with automake to generate Makefile.in
 
 AUTOMAKE_OPTIONS = cygnus
 
 if HAVE_POSIX_DIR
 POSIX_SUBDIR = posix
 endif
 
 if HAVE_SIGNAL_DIR
 SIGNAL_SUBDIR = signal
@@ skipping 99 matching lines @@
          for i in $(SUBLIBS); do \
            $(AR) x ../$$i; \
          done; \
         $(AR) $(AR_FLAGS) ../$@ *.o
         $(RANLIB) $@
         rm -rf tmp
 endif # USE_LIBTOOL
 
 $(SUBLIBS): ; @true
 
-crt0.o: sys/crt0.o
+crt0.o: $(wildcard sys/crt0.o)
         rm -f $@
-        ln sys/crt0.o $@ >/dev/null 2>/dev/null || cp sys/crt0.o $@
+        if test -f sys/crt0.o; then ln sys/crt0.o $@ >/dev/null 2>/dev/null || cp sys/crt0.o $@; fi
 
 sys/crt0.o: ; @true
 
 # This is a list of the stmp-def files in each subdirectory which
 # builds .def files.  We don't list subdirectories which don't build
 # .def files; if the list of subdirectories changes, we must change
 # this as well.
 SUBDEFS = \
         stdlib/stmp-def \
         ctype/stmp-def \
@@ skipping 94 matching lines @@
 force:
 
 CLEANFILES = $(CRT0) \
         sigset.texi stmp-sigset extra.texi stmp-extra \
         stdio64.texi stmp-stdio64 targetdep.tex stmp-targetdep \
         tmp-sigset.texi tmp-iconvset.texi tmp-extra.texi \
         tmp-stdio64.texi tmp-posix.texi tmp-targetdep.texi
 
 ACLOCAL_AMFLAGS = -I .. -I ../..
 CONFIG_STATUS_DEPENDENCIES = $(newlib_basedir)/configure.host