Explicitly include gcc

ck.spec

@@ -1,6 +1,6 @@
 Name: ck
 Version: 0.6.0
-Release: 6%{?dist}
+Release: 7%{?dist}
 Summary: Library for high performance concurrent programming
 
 Group: Development/Libraries
@@ -11,6 +11,8 @@ Source: http://concurrencykit.org/releases/ck-%{version}.tar.gz
 Patch0: ck-config-s390x.patch
 Patch1: ck-ppc64.patch
 
+BuildRequires: gcc
+
 %description
 Concurrency Kit provides a plethora of concurrency primitives, safe memory
 reclamation mechanisms and lock-less and lock-free data structures designed to
@@ -76,6 +78,9 @@ make check
 %postun -p /sbin/ldconfig
 
 %changelog
+* Tue Jul 17 2018 Honza Horak <hhorak@redhat.com> - 0.6.0-7
+- Explicitly include gcc
+
 * Tue Jul 17 2018 Honza Horak <hhorak@redhat.com> - 0.6.0-6
 - Fix building on s390x and use -O0 for ppc64le