removed explicit version checks of dependencies such as serpent

Author: irmen

docs/source/changelog.rst

@@ -5,6 +5,8 @@ Change Log
 **Pyro 4.79**
 
 - cython compatibility fix
+- removed explicit version checks of dependencies such as serpent.
+  This fixes crash error when dealing with prerelease versions that didn't match the pattern.
 
 
 **Pyro 4.78**

src/Pyro4/util.py

@@ -820,27 +820,16 @@ def get_serializer_by_id(sid):
     pass
 try:
     import serpent
-    if '-' in serpent.__version__:
-        ver = serpent.__version__.split('-', 1)[0]
-    else:
-        ver = serpent.__version__
-    ver = tuple(map(int, ver.split(".")))
-    if ver < (1, 27):
-        raise RuntimeError("requires serpent 1.27 or later")
     _ser = SerpentSerializer()
     _serializers["serpent"] = _ser
     _serializers_by_id[_ser.serializer_id] = _ser
 except ImportError:
     log.warning("serpent serializer is not available")
 try:
     import msgpack
-    if msgpack.version < (0, 5, 2):
-        import warnings
-        warnings.warn("msgpack serializer unavailable. requires msgpack 0.5.2+, found " + str(msgpack.version))
-    else:
-        _ser = MsgpackSerializer()
-        _serializers["msgpack"] = _ser
-        _serializers_by_id[_ser.serializer_id] = _ser
+    _ser = MsgpackSerializer()
+    _serializers["msgpack"] = _ser
+    _serializers_by_id[_ser.serializer_id] = _ser
 except ImportError:
     pass
 del _ser