I was struggling to debug my custom action class... Oh gush real pain How to debug this stuff.. i searched and got the simple way to debug Windows Installer (MSI) is to put below cool line in begining of your custom action class code
"Debugger.Break" !!! and you are ready to go...
I know that you can set an environment variable on the cmd line equal to name of a custom action inside your msi package. Once the Msi starts running and it reaches that custom action, it breaks into your registered debugger. I have been looking for the name of this environment variable, but I can't find it anywhere in the MSDN library..
I found it!
set MsiBreak=<name of your custom action>
