better fix for old libraries of compat mode

configure/os/CONFIG.RHEL10-x86_64.RHEL8-x86_64

@@ -21,5 +21,6 @@ CPPFLAGS += $(WRAPPER)
 AR = ar -rc
 RANLIB = ranlib
 
-# Allow to run cross-tests which expect different lib versions
-export LD_PRELOAD=$(SYSROOT)/lib64/libreadline.so
+# Allow RHEL8 EPICS programs to find older libraries
+# --disable-new-dtags extends -rpath to indirect depencencies
+LDFLAGS += -Wl,--disable-new-dtags -Wl,-rpath=/lib64:$(SYSROOT)/lib64 -Wl,-rpath-link,$(SYSROOT)/lib64 

configure/os/CONFIG.RHEL9-x86_64.RHEL8-x86_64

@@ -21,5 +21,6 @@ CPPFLAGS += $(WRAPPER)
 AR = ar -rc
 RANLIB = ranlib
 
-# Allow to run cross-tests which expect different lib versions
-export LD_PRELOAD=$(SYSROOT)/lib64/libreadline.so
+# Allow RHEL8 EPICS programs to find older libraries
+# --disable-new-dtags extends -rpath to indirect depencencies
+LDFLAGS += -Wl,--disable-new-dtags -Wl,-rpath=/lib64:$(SYSROOT)/lib64 -Wl,-rpath-link,$(SYSROOT)/lib64 

epics-base.spec

@@ -90,6 +90,7 @@ Contains headers etc to build EPICS host applications.
 %package compat
 Summary:        EPICS base %{EpicsVersion} for older RHEL versions
 Requires:       %{name} = %{version}-%{release}
+Requires:       gfa-cross-compiler-links
 AutoReqProv:    no
 
 %description compat
@@ -232,13 +233,8 @@ shopt -s extglob
 /bin/sed 's!@EPICS_BASE@!%{prog_folder}!g;s!@EPICS_HOST_ARCH@!%{epics_host_arch}!g' epics-base.sh > %{buildroot}%{prog_folder}/bin/epics-base.sh
 chmod +x %{buildroot}%{prog_folder}/bin/epics-base.sh
 
-# copy over old libraries for compatibility
-%if 0%{?rhel} > 8
-%{__cp} /opt/RHEL8/lib64/libreadline.so.7 %{buildroot}%{prog_folder}/lib/RHEL8-x86_64
-%endif
-
 # Do not use install section because build already installed
-# and install will delete our buildroot!
+# and install would delete our buildroot!
 
 %clean
 %make_build INSTALL_LOCATION=%{buildroot}%{prog_folder} realclean