title: Intellij reports Rust toolchain not installed, even though I just installed it
body: <p>I'm programming Rust in IntelliJ, on Windows 10. Trying to switch to the nightly channel so I can use some nightly features. But I can't get it to compile in nightly. This picture says it all:</p>
  
  <p><a href="https://i.stack.imgur.com/OXK6S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OXK6S.png" alt="enter image description here"></a></p>
  
  <p>On the right, we have IntelliJ telling me: error: toolchain 'nightly-x86_64-pc-windows-msvc' is not installed</p>
  
  <p>On the left, we have me just having had installed nightly-x86_64-pc-windows-msvc.</p>
  
  <p>I've tried restarting my computer, IDE, uninstalling and reinstalling, etc. I've tried setting path variables, in my system, and in the IntelliJ run config. I'm still bamboozled.</p>
  
  <p>Any suggestions?</p>