Write date to file with xbuild -

i'm using xbuild 12 in monodevelop 5.9.6. yes, it's old. no, can't upgrade. :)

i want write current date file on build. i've set this, googling msbuild:

<target name="afterbuild">   <writelinestofile file="$(outputpath)\version.txt" lines="$([system.datetime]::now.tostring())" overwrite="true" /> </target> 

however when build in monodevelop, error:

error: error executing task writelinestofile: error converting property named 'lines' value '$([system.datetime]::now.tostring())' type microsoft.build.framework.itaskitem[]: requested feature not implemented. (server) 

so looks i'm out of luck? there functional way xbuild can this? preferably custom formatting. 1 fallback use run tiny python script instead, it's starting rube goldbergy.

it seems version doesn't support property functions. on mac/linux use:

<target name="afterbuild">     <exec command="date > $(outputpath)\version.txt" />  </target>