ironpython3 Update docs to specify versions of Mono that can be used

Hi,

I tried the following to build the code:

git clone [...] --recurse
make

I get an error, with very little information:

Configuration: Debug Platform: AnyCPU
		Configuration: Debug Platform: AnyCPU
Makefile:4: recipe for target 'debug' failed
make: *** [debug] Error 1

What exactly does this mean? I checked the Makefile and ran line 4 (xbuild Build.proj /t:Build /p:Mono=true /p:BuildFlavour=Debug /p:Platform="Any CPU" /verbosity:minimal /nologo) manually, but it just prints the same first two lines (configuration: Debug ...) and nothing apparently happens.

Mar 30 '17 14:03 ashes999

Did you do a submodule initialization for the DLR sources?

Mar 30 '17 14:03 slide

Yes. I believe git checkout [...] --recurse included the submodules, because without this, I got a build failure about something missing from the DLR directory (which was empty).

Mar 30 '17 15:03 ashes999

What version of mono do you have installed?

Mar 31 '17 14:03 slide

mono --version tells me Mono JIT compiler version 4.2.1 (Debian 4.2.1.102+dfsg2-7ubuntu4)

Mar 31 '17 15:03 ashes999

I believe you need at least 4.6 for IronPython

Mar 31 '17 15:03 slide

Looks like you're right. I can build the proposed fix after upgrading to Mono 4.8.

Mar 31 '17 15:03 ashes999

We need to update our docs to specify the minimum Mono version, so I'll leave this open.

Mar 31 '17 15:03 slide