Fix test and avoid yacc table mismatch

- Add build dependency on cpp for unit tests
- Add dependency on python-ply version to prevent "yacc table file version is out of date"
- Fixes RHBZ#1668230

python-pycparser.spec

@@ -2,10 +2,14 @@
 %global with_python3 1
 %endif
 
+# Ensure that pycparser uses the same YACC __tabversion__ as python-ply
+# package to prevent "yacc table file version is out of date" problem.
+%define ply_version %(LC_ALL=C rpm -q --qf '%%{VERSION}' python3-ply | grep -Eo '^[^.]+\.[^.]+')
+
 Name:           python-pycparser
 Summary:        C parser and AST generator written in Python
 Version:        2.14
-Release:        17%{?dist}
+Release:        18%{?dist}
 License:        BSD
 URL:            http://github.com/eliben/pycparser
 Source0:        http://github.com/eliben/pycparser/archive/release_v%{version}.tar.gz
@@ -23,6 +27,7 @@ BuildRequires:  python2-devel python2-setuptools
 # for unit tests
 BuildRequires:  dos2unix
 BuildRequires:  python2-ply >= 3.6
+BuildRequires:  cpp
 
 %if 0%{?with_python3}
 BuildRequires:  python3-devel python3-setuptools
@@ -37,7 +42,7 @@ need to parse C source code.
 
 %package -n python2-pycparser
 Summary:        C parser and AST generator written in Python
-Requires:       python2-ply >= 3.6
+Requires:       python2-ply = %{ply_version}
 %{?python_provide:%python_provide python2-pycparser}
 
 %description -n python2-pycparser
@@ -48,7 +53,7 @@ need to parse C source code.
 %if 0%{?with_python3}
 %package -n python3-pycparser
 Summary:        C parser and AST generator written in Python
-Requires:       python3-ply
+Requires:       python3-ply = %{ply_version}
 %{?python_provide:%python_provide python3-pycparser}
 
 %description -n python3-pycparser
@@ -110,6 +115,11 @@ popd
 %endif # with_python3
 
 %changelog
+* Tue Feb 26 2019 Christian Heimes <cheimes@redhat.com> - 2.14-18
+- Add build dependency on cpp for unit tests
+- Add dependency on python-ply version to prevent "yacc table file version is out of date"
+- Fixes RHBZ#1668230
+
 * Sat Feb 02 2019 Fedora Release Engineering <releng@fedoraproject.org> - 2.14-17
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_30_Mass_Rebuild