Requires tar, which is not installed in an @Core installation.

supermin.spec

@@ -1,7 +1,7 @@
 Summary:       Tool for creating supermin appliances
 Name:          supermin
 Version:       5.1.6
-Release:       4%{?dist}
+Release:       5%{?dist}
 License:       GPLv2+
 
 %if 0%{?rhel} >= 7
@@ -33,6 +33,7 @@ Requires:      rpm
 Requires:      yum-utils
 Requires:      util-linux-ng
 Requires:      cpio
+Requires:      tar
 Requires:      /usr/sbin/mke2fs
 # RHBZ#771310
 Requires:      e2fsprogs-libs >= 1.42
@@ -89,6 +90,9 @@ make check || {
 
 
 %changelog
+* Thu Apr  3 2014 Richard W.M. Jones <rjones@redhat.com> - 5.1.6-5
+- Requires tar, which is not installed in an @Core installation.
+
 * Fri Mar 28 2014 Richard W.M. Jones <rjones@redhat.com> - 5.1.6-4
 - Add upstream patch to fix supermin on ppc64p7.