Custom MSBuild Task: how to flush logging in VS2012 output window while task is still running?

Question

I have a custom MSBuild task that takes some time to complete. It outputs progress using either Log.LogMessage() or BuildEngine.LogMessageEvent() (

Answer 1

Known bug in VS2012.

We ended up making a VSPackage extension for VS2012/2013 (to directly output in pane log).

It is fixed in VS2015.

Answer 2

It is a bug in VS 2012. In the comments in this bug report a user whose alias is Will, speaking on behalf of Microsoft, wrote on July the 2nd of 2013 that Though we will not have a chance to address this issue in Visual Studio 2012, we will consider this feedback when planning for future versions of Visual Studio.