<!-- If we're on Visual Studio 2015 RTM and we still have Roslyn installed, our VSIX-producing packages are not going to install, so let's not even try.
Update 1 supports this, so we'll use csi.exe's existence as a simple proxy for whether we have Update 1 installed or not. -->
<DeployExtension Condition="'$(DeployExtension)' == '' AND Exists('$(DevEnvDir)\CommonExtensions\Microsoft\Roslyn\Language Services\extension.vsixmanifest') AND !Exists('$(MSBuildBinPath)\csi.exe')">false</DeployExtension>
<!-- If we're on Visual Studio 2015 RTM and we still have Roslyn installed, our VSIX-producing packages are not going to install, so let's not even try.
Update 1 supports this, so we'll use csi.exe's existence as a simple proxy for whether we have Update 1 installed or not. -->
<DeployExtension Condition="'$(DeployExtension)' == '' AND Exists('$(DevEnvDir)\CommonExtensions\Microsoft\Roslyn\Language Services\extension.vsixmanifest') AND !Exists('$(MSBuildBinPath)\csi.exe')">false</DeployExtension>