clingo: fix ~python build (#30824)

.github/workflows/bootstrap.yml

@@ -12,6 +12,7 @@ on:
       # built-in repository or documentation
       - 'var/spack/repos/builtin/**'
       - '!var/spack/repos/builtin/packages/clingo-bootstrap/**'
+      - '!var/spack/repos/builtin/packages/clingo/**'
       - '!var/spack/repos/builtin/packages/python/**'
       - '!var/spack/repos/builtin/packages/re2c/**'
       - 'lib/spack/docs/**'

var/spack/repos/builtin/packages/clingo/package.py

@@ -86,15 +86,19 @@ def cmake_args(self):
         except UnsupportedCompilerFlag:
             InstallError('clingo requires a C++14-compliant C++ compiler')
 
-        args = [
+        args = ['-DCLINGO_BUILD_WITH_LUA=OFF']
+
+        if '+python' in self.spec:
+            args += [
                 '-DCLINGO_REQUIRE_PYTHON=ON',
                 '-DCLINGO_BUILD_WITH_PYTHON=ON',
                 '-DPYCLINGO_USER_INSTALL=OFF',
                 '-DPYCLINGO_USE_INSTALL_PREFIX=ON',
-            '-DCLINGO_BUILD_WITH_LUA=OFF',
                 self.cmake_py_shared
             ]
             if self.spec['cmake'].satisfies('@3.16.0:'):
                 args += self.cmake_python_hints
+        else:
+            args += ['-DCLINGO_BUILD_WITH_PYTHON=OFF']
 
         return args