There seems to be an incompatibility with the test results reported by Nunit3 Console/Nunit-v2-result-writer and the XUnit plugin.

When the Nunit-v2-result-writer fails to provide a nunit version number to the output xml (because the following issue is occuring in the Nunit writer https://github.com/nunit/nunit-v2-result-writer/issues/35) the Xunit Plugin then throws this error: 

ERROR: Conversion error: Cannot convert string "" to double

Here's a sample of the XML output with the missing nunit-version

<environment nunit-version="" clr-version="4.0.30319.42000" os-version="Microsoft Windows NT 6.2.9200.0" platform="Win32NT" cwd="D:\git\Api\Api.UnitTests" machine-name="DEV" user="couper" />

Is this something the xUnit plugin can guard against and not fail the pipeline, or is this variable required as part of the XSD.  

https://github.com/jenkinsci/xunit-plugin/blob/447b4cb26d9669df8c9c6118f6d0c7ce144a05d8/src/main/resources/org/jenkinsci/plugins/xunit/types/nunit-2.x-to-junit.xsl#L73

Thank you.