This post is about Umbraco 7 installation. Its an obscure one so I thought I would mention it here to aid folk in the future.
Basically when you install Umbraco from NuGet and you come across the following error.
Install failed. Rolling back... install-package : Expected "$(_PublishProfileSet)" to evaluate to a boolean instead of "", in condition "$(_PublishProfileSet) And '$(PublishProfileName)' =='' And '$(WebPublishProfileFile)'==''". C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v12.0\Web\Microsoft.Web.Publishing.targets At line:1 char:1 + install-package umbracocms + ~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [Install-Package], InvalidProjectFileException + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
It's a known conflict error between Resharper and the install. Further details can be found here. But in brief. Disable Resharper and try again.
Worked for me. I believe the issue is resolved in v9 of ReSharper but further comments would be appreciated.
To disable/Suspend ReSharper
Navigate to: Tools -> Options -> ReSharper -> Suspend Now