SRPM on SLC6 only depends on packages required by cta command-line tool

cta.spec.in

@@ -25,8 +25,17 @@ Release: %{ctaRelease}%{mydist}
 Source: %{name}-%{ctaVersion}-%{ctaRelease}.tar.gz
 License: GPLv3+
 Group: Application/cta
+
 BuildRoot: %{_builddir}/%{name}-%{version}-root
 BuildRequires: cmake >= 2.6 redhat-rpm-config
+
+
+# The CTA client is the only component of CTA that can be compiled on both SLC6
+# and C77, therefore only the packages it depends on are required for SLC6
+%if "%{?dist}" == ".slc6" || "%{?dist}" == ".el6"
+BuildRequires: xrootd-client-devel >= 4.2.3 xrootd-devel >= 4.2
+BuildRequires: cryptopp-devel >= 5.6.2
+%else
 BuildRequires: xrootd-client-devel >= 4.2.3 xrootd-devel >= 4.2
 BuildRequires: xrootd-server-devel >= 4.2 xrootd-private-devel >= 4.2
 BuildRequires: librados2-devel >= 0.80
@@ -42,6 +51,7 @@ BuildRequires: libuuid-devel >= 2.17
 BuildRequires: json-c-devel >= 0.11
 BuildRequires: libattr-devel >= 2.4.44
 BuildRequires: oracle-instantclient12.1-devel
+%endif
 # only build debug info if you're building the whole code
 
 %description