Require grass version in BR instead of Req

This will avoid building with a different version than intended.
The sub-package dependencies is taken care of by soname versions.

qgis.spec

@@ -11,6 +11,12 @@
 %endif
 %endif
 
+
+# WARNING: Rebuild QGIS whenever a new version of GRASS is shipped! Even though
+# the soname might stay the same, it won't work anymore.
+#http://hub.qgis.org/issues/5274
+%global grass_version 7.0.4
+
 #TODO: Run test suite (see debian/rules)
 
 Name:           qgis
@@ -50,7 +56,7 @@ BuildRequires:  fcgi-devel
 BuildRequires:  flex bison
 BuildRequires:  gdal-devel
 BuildRequires:  geos-devel
-BuildRequires:  grass-devel
+BuildRequires:  grass-devel = %{grass_version}
 BuildRequires:  gsl-devel
 
 %ifarch ppc ppc64
@@ -127,12 +133,8 @@ Group:          Applications/Engineering
 Requires:       %{name}%{?_isa} = %{version}-%{release}
 
 # The plug-in requires more than just the grass-libs.
-# This questions the sense of the libs package is questionable
-
-# WARNING: Rebuild QGIS whenever a new version of GRASS is shipped! Even though
-# the soname might stay the same, it won't work anymore.
-#http://hub.qgis.org/issues/5274
-Requires:       grass = 7.0.4
+# This questions the sense of the libs package.
+Requires:       grass
 
 %description grass
 GRASS plugin for QGIS required to interface with the GRASS system.
@@ -406,6 +408,11 @@ update-mime-database %{?fedora:-n} %{_datadir}/mime &> /dev/null || :
 
 
 %changelog
+* Mon Jun 06 2016 Volker Froehlich <volker27@gmx.at> - 2.14.3-2
+- Move grass version to BR. This will avoid building with a
+  different version than intended. The sub-package dependencies
+  is taken care of by soname versions.
+
 * Mon May 23 2016 Volker Froehlich <volker27@gmx.at> - 2.14.3-1
 - New upstream release