MSBuild 14.0 (the version included with Visual Studio 2015) logs warnings (MSB4078) when building a solution which contains SSDT projects (rptproj or dwproj projects). For examp
Skipping projects can be done with /ignoreprojectextensions:.rptproj
, but I still get the warning (on VS2015) so presumably you would still get the error.
What is possible is to specify a list of the ones you do want to build with
msbuild /t:myCsProj /t:mySqlProj /t:myOtherProjThatIsntaRptProj
Whether or not this is viable, of course, depends on how many "other" projects you have in your solution.
Alternatively, there are some ways of bodging MSBuild to be able to cope with other project types (e.g. https://speaksql.wordpress.com/2013/06/07/a-journey-to-db-deployment-automaton-ssis-build-using-msbuild/).
I've seen this approach "in the wild" a couple of times, but only ever for SSIS. I have heard it can be made to work for SSRS/SSAS too though.