HOW TO: Debug a Windows Installer custom action

Monday, 28 June 2010 Edited Sunday, 29 January 2023 .net software development wix

Prerequisites:

Determine the name of the custom action you want to debug
Ensure you have the source code and debug symbols for your custom action

Steps

Set the MsiBreak environment variable (user or system) to the name of the custom action. For example, if your custom action is called MyCustomAction:

Error: no lexer for alias 'cmd' found

Run your installer and wait for the message box prompt

Details

When your custom action is about to execute, you should get this message box prompt:

Debugging Custom Actions

Now you can use Visual Studio or another debugger such as WinDBG to attach to the specified process.

References:

Debugging Custom Actions @ msdn.microsoft.com