This project has moved. For the latest updates, please go here.
Hello IronPython Community,

We’re pleased to announce the release of IronPython 2.0 Release Candidate 1. We have fixed around 40 bugs since the previous beta. There have been more than 500 bug fixes since the first 2.0 alpha was announced. Apart from the bug fixes these items have also been addressed:
  • The problem caused by ExtensionAttribute while using IronPython in a .NET 3.5 project that references System.Core has been fixed by moving that type to a new assembly called Microsoft.Scripting.ExtensionAttribute.dll. If you are referencing System.Core you should not reference this assembly while building it but while deploying your application, this assembly needs to be deployed as well. Harry has more details here.
  • The MSI installer now has an option to ngen the installed binaries. Ngen’ing the dlls gives a significant startup performance boost. The option is turned off by default but if no issues are reported, we’ll enable it by default in a future release.
  • The CPython standard library modules and packages that cannot be imported in IronPython currently have been removed from the MSI installation. The complete list is here
  • The DLR sample language ToyScript is included in this release in a separate zip file. This is a temporary arrangement till the sample finds a more permanent home. For the references in the ToyScript project to line up, unzip it to the Src folder of the IronPython source release.

If no major issues with the RC are reported, we hope to ship the final 2.0 release in around a month’s time. Anyone planning to move to 2.0 please try the RC and let us know of any issues you find.

These bugs have been closed since the previous release:
  • 2021 Incorrect rmul invocation for multiplication
  • 8098 Exceptions not Serializable
  • 11016 IronPython uses "\r\r\n" as a line separator instead of os.linsep ("\r\n" on Windows)
  • 11971 Array doesn't have methods w/o importing clr
  • 14144 time.strftime("%w") bug
  • 14196 Add iter to items that support IEnumerable but aren't indexable (e.g. Stack)
  • 15995 Trivial: Different exception thrown by ipy for deque.remove
  • 16371 DUPLICATE: time.strftime throws a ValueError while CPy doesnt
  • 16476 Trivial: struct.unpack('I', s) should return int if possible
  • 16563 Trivial: help(System.DateTime.Parse)
  • 16693 "yield" in IronPython-2.0B2 broken when yielding global variables
  • 17355 contains on locals() returns True for globals() when called inside a function
  • 17740 Relative imports don't work properly when there are two modules with the same name
  • 17781 Horrible performance regression of exec
  • 17797 clr.CompileModules is not part of TabCompletion
  • 17819 DUPLICATE: relative imports don't work inside directory package
  • 17911 '+' operator no longer supports str and Char as operands
  • 17963 new.instance(..., None).dict throws a SystemError
  • 17964 new.instancemethod(someFunction, None) should not be allowed
  • 18132 New-style classes can't inherit from only old-style classes and use metaclass
  • 18133 Do not mention IronPython types in the TypeError message emitted from the type function
  • 18217 CPython's spawns assert windows and hangs
  • 18312 str(newStyleClass.dict) is wrong when there is a recursive reference
  • 18313 dict of new style classes don't have iteritems(), iterkeys() or itervalues()
  • 18314 .NET Structs that have a default indexer don't support enumeration
  • 18326 sys.meta_path objects break when relative imports are utilized
  • 18327 Cannot reload modules which are created by objects in sys.path_hooks
  • 18331 unicode('\\', 'rawunicodeescape') throws an error
  • 18333 decoding of 'unicode_internal' strings is broken
  • 18350 Innacuracy in float representation (causing pickle problems)
  • 18517 -X:ExceptionDetail behaves differently depending upon the OS (or CLR minor version)
  • 18523 Case insensitive ipy.exe tab completion broken
  • 18524 COM methods don't work on x64 platforms
  • 18575 Compiling modules with cyclic imports inside a package fails
  • 18576 compiling a package with sub-packages doesnt preserve the hierarchy.
  • 18639 COM methods can't correctly be used as Python dict keys under -X:PreferComInteropAssembly
  • 18728 hmac module broken
  • 18747 Regular expression repeat qualifier {m,n} does not work if lower bound is omitted

We’d like to thank everyone in the community who reported these bugs: sanxiyn, Michael Foord, jtenney, yanne, zpy, atifaziz, srid, Eloff, Korbinian, sdahlbac and baxeno.

These bugs were reported internally and closed:
  • 409568 test_parrot fails under -X:Interpret (Debug binaries on 64-bit platforms) w/ StackOverflowException
  • 436524 broken by merged SNAP job (changeset 435597)
  • 497193 tf changeset 533300 caused 60% perf degrade in IronPython startup time

You can download IronPython 2.0 RC1 at:

The IronPython Team

Last edited Oct 22, 2008 at 9:07 PM by srivatsn, version 5


No comments yet.