spec file fixes: exit postun cleanly, host-devel loads compat, build needs gfa-cross-compiler-links

epics-base.spec

@@ -52,6 +52,11 @@ Requires:       readline-devel
 Summary:    Minimal stuff needed to build EPICS host apps
 Requires:   %{name} = %{version}-%{release}
 
+%if 0%{?rhel} > 8
+# Have the older host versions available
+Requires:       %{name}-compat
+%endif
+
 %if 0%{?rhel} >= 8 && 0%{?rhel} <= 9
 # This EPICS installation uses the toolset 12 compiler
 Requires:       gcc-toolset-12-gcc-c++
@@ -125,6 +130,7 @@ This package can be relocated.
 Summary:        EPICS base %{EpicsVersion} for development environments
 Requires:       %{name}             = %{version}-%{release}
 Requires:       %{name}-host-devel  = %{version}-%{release}
+BuildRequires:  gfa-cross-compiler-links
 Requires:       gfa-cross-compiler-links
 BuildArch:      noarch
 AutoReqProv:    no
@@ -251,7 +257,7 @@ then
 fi
 
 %postun
-[ "$1" -eq 0 ] || exit
+[ "$1" -eq 0 ] || exit 0
 shopt -s extglob
 %{__rm} -f /etc/profile.d/epics-base.sh
 %{__ln_s} "$(/usr/bin/ls -dvr1 /usr/local/epics/base-+([0-9]).+([0-9]).+([0-9])/bin/epics-base.sh 2>/dev/null | /usr/bin/head -n1)" /etc/profile.d/ 2>/dev/null