rebuild cython extensions when python/cython/distuils change

.gitignore

@@ -14,4 +14,3 @@ can/packer_pyx.cpp
 can/parser_pyx.cpp
 can/packer_pyx.html
 can/parser_pyx.html
-can/packer_impl.cpp

SConstruct

@@ -1,9 +1,16 @@
+import Cython
+import distutils
 import os
 import subprocess
+import sys
 
 zmq = 'zmq'
 arch = subprocess.check_output(["uname", "-m"], encoding='utf8').rstrip()
 
+# Rebuild cython extensions if python, distutils, or cython change
+cython_dependencies = [Value(v) for v in (sys.version, distutils.__version__, Cython.__version__)]
+Export('cython_dependencies')
+
 cereal_dir = Dir('.')
 
 cpppath = [

can/SConscript

@@ -1,4 +1,4 @@
-Import('env', 'cereal')
+Import('env', 'cereal', 'cython_dependencies')
 
 import os
 from opendbc.can.process_dbc import process
@@ -17,7 +17,6 @@ for x in sorted(os.listdir('../')):
 libdbc = env.SharedLibrary('libdbc', ["dbc.cc", "parser.cc", "packer.cc", "common.cc"]+dbcs, LIBS=["capnp", "kj"])
 
 # Build packer and parser
-
-env.Command(['packer_pyx.so', 'parser_pyx.so'],
-  [libdbc, cereal, 'common_pyx_setup.py', 'packer_pyx.pyx', 'parser_pyx.pyx', 'common.pxd'],
-  "cd opendbc/can && python3 common_pyx_setup.py build_ext --inplace")
+env.Command(['packer_pyx.so', 'packer_pyx.cpp', 'parser_pyx.so', 'parser_pyx.cpp'],
+            cython_dependencies + [libdbc, cereal, 'common_pyx_setup.py', 'common.pxd', 'packer_pyx.pyx', 'parser_pyx.pyx'],
+            "cd opendbc/can && python3 common_pyx_setup.py build_ext --inplace")