# IronRuby v2Release xbuild is failing **URL:** \ **Category:** IronRuby\ **Created:** [October 3, 2011, 10:38pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462 "2011-10-03T22:38:29Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\ **Post date:** [October 3, 2011, 10:38pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/1 "2011-10-03T22:38:29Z")
FYI, When trying to build IronRuby for a v2Release under Mono 2.10.2, I’m getting a failure: % git clone [GitHub - IronLanguages/main: Work for this repo has moved to https://github.com/IronLanguages/ironpython2](https://github.com/IronLanguages/main.git) IronLanguages % cd IronLanguages % xbuild Solutions/Ruby.sln /p:Configuration=“v2Release” … Builtins/RangeOps.cs(307,17): error CS0266: Cannot implicitly convert type `System.Collections.Generic.IEnumerable' to `System.Collections.Generic.IEnumerable'. An explicit conversion exists (are you missing a cast?) Building for the regular configuration is fine. -Doug ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 5:11pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/2 "2011-10-05T17:11:18Z")
Reported as: [http://ironruby.codeplex.com/workitem/6523](http://ironruby.codeplex.com/workitem/6523) -Doug ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 5:16pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/3 "2011-10-05T17:16:15Z")
Can someone sign up to looking into this? After confirming this builds in .NET and not Mono, I’d first find out if this is a known Mono bug, and then provide a patch to IronRuby to work-around this. Please let the list know if you want to take this on, ~js ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 6:12pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/4 "2011-10-05T18:12:29Z")
Is “v2Release” intended to target CLRv2? If so, this error is because that version of C# and the BCL don’t support covariance for IEnumerable. ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 8:32pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/5 "2011-10-05T20:32:09Z")
On Wed, Oct 5, 2011 at 11:17 AM, Curt H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Is “v2Release” intended to target CLRv2? If so, this error is because that > version of C# and the BCL don’t support covariance for IEnumerable. I believe that “v2Release” targets the 3.5 framework (is that the same as CLRv2?), but someone can correct me if I am wrong. I’m currently running a previous version of IronRuby built for “v2Release”, so perhaps there is at least a patch that we can apply (will a simple cast be sufficient?). I’m trying to build the latest versions of IronRuby and IronPython for inclusion into the next version of Ubuntu. The versions built on dlr-0.9 were just removed. However, I must admit that I don’t know if people will really need v2Releases… I just thought I’d build them if I could. -Doug ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 9:45pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/6 "2011-10-05T21:45:41Z")
> Is downlevel-framework support still a goal for IronRuby? I seem to recall that > IronPython 2.7 is .NET 4.0-only. We were keeping around \< 4.0 support for Windows Phone. It’s always up for discussion whether we continue doing that; I vote yes. ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 8:59pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/7 "2011-10-05T20:59:55Z")
Yep, .NET 2.0, 3.0 and 3.5 all share the same fundamental CLR and the BCL bits are strictly additive. A simple cast is not sufficient; the code will need modification. One approach would be to insert a 3.5-only adapter function which does something like this: IEnumerable Convert(IEnumerable collection) { foreach (var item in collection) { yield return item; } } (I’d need to refer to the context of the code to make any other suggestions.) Is downlevel-framework support still a goal for IronRuby? I seem to recall that IronPython 2.7 is .NET 4.0-only. ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 6, 2011, 12:23am UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/8 "2011-10-06T00:23:12Z")
On Wed, Oct 5, 2011 at 11:35 AM, Curt H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Is downlevel-framework support still a goal for IronRuby? I seem to recall that > IronPython 2.7 is .NET 4.0-only. IronPython only ‘officially’ supports 4, but we occasionally make sure that it compiles for 3.5 as well (usually when someone points out that it’s broken). There are a couple of embedders that haven’t moved their host apps to 4 yet, but are fine to build IronPython themselves for 3.5. - Jeff ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [October 5, 2011, 10:32pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/9 "2011-10-05T22:32:01Z")
On Wed, Oct 5, 2011 at 2:35 PM, Curt H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Yep, .NET 2.0, 3.0 and 3.5 all share the same fundamental CLR and the BCL bits > are strictly additive. A simple cast is not sufficient; the code will need > modification. One approach would be to insert a 3.5-only adapter function which > does something like this: > > IEnumerable Convert(IEnumerable collection) { > foreach (var item in collection) { > yield return item; > } > } > > (I’d need to refer to the context of the code to make any other suggestions.) Ok, thanks. > Is downlevel-framework support still a goal for IronRuby? I seem to recall that > IronPython 2.7 is .NET 4.0-only. There are many systems still using Mono 2.6.7 which is CLRv2. However, I think that this may change sooner than later as distros like Ubuntu are moving on up. -Doug ---
**Author:** ![ashiro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e5b9ba/32.png) [@ashiro](https://www.ruby-forum.com/u/ashiro)\ **Post date:** [November 13, 2011, 5:11pm UTC](https://www.ruby-forum.com/t/ironruby-v2release-xbuild-is-failing/212462/10 "2011-11-13T17:11:37Z")
On Wed, Oct 5, 2011 at 11:10 AM, Doug B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Reported as: > [http://ironruby.codeplex.com/workitem/6523](http://ironruby.codeplex.com/workitem/6523) Updated this workitem: This build issue with Ruby, under Mono, with /p:Configuration=“v2Release” can be fixed with: change: #if SILVERLIGHT return EachStepString(storage, self, ConvertStepToInt(storage, step)).Cast(); #else return EachStepString(storage, self, ConvertStepToInt(storage, step)); #endif to just: ``` return EachStepString(storage, self, ``` ConvertStepToInt(storage, step)).Cast(); This may turn out to be more important than first thought, as having some trouble using Configuration v4 under Mono (it builds fine, but having trouble with integration with other DLLs, probably because of v2 vs v4 issues). Looking into that, but we will need to use v2 for the time being. -Doug