I attempted to update Visual Studio Build Tools 2017 and whenever the installer runs it runs at 100% cpu and takes an immense amount of time to work, if it all.
What I've tried:
Uninstalling the installer and visual studio 2017
Cleaning the install and rerunning it with the clean utility
Trying to run it in --quiet mode with my chosen packages stopping my CI server and Octopus deploy
On any other machine it works quickly but on my build server it kills the cpu.
Setting the CPU priority of vs_installershell.exe to idle caused it to start working correctly.