Checking out Cython from master (the 0.23.x branch works fine) and running "python setup.py install" gives me Unable to find pgen, not compiling formal grammar. Compiling module Cython.Compiler.Scanning ... ERROR: 'module' object has no attribute 'CCodeConfig' Extension module compilation failed, looks like Cython cannot run properly on this system. To work around this, pass the option "--no-cython-compile". This will install a pure Python version of Cython without compiling its own sources. Traceback (most recent call last): File "setup.py", line 289, in <module> compile_cython_modules(cython_profile, cython_compile_more, cython_with_refnanny) File "setup.py", line 233, in compile_cython_modules result = compile(pyx_source_file) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/Main.py", line 677, in compile return compile_single(source, options, full_module_name) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/Main.py", line 630, in compile_single return run_pipeline(source, options, full_module_name) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/Main.py", line 487, in run_pipeline err, enddata = Pipeline.run_pipeline(pipeline, source) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/Pipeline.py", line 334, in run_pipeline data = phase(data) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/Pipeline.py", line 53, in generate_pyx_code_stage module_node.process_implementation(options, result) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/ModuleNode.py", line 118, in process_implementation self.generate_c_code(env, options, result) File "/usr/local/src/sage-git/local/src/cython/Cython/Compiler/ModuleNode.py", line 317, in generate_c_code c_code_config = Code.CCodeConfig( AttributeError: 'module' object has no attribute 'CCodeConfig'