Debugging MSBuild scripts

If you want to debug an MSBuild script from without Visual Studio, you need to use the /debug command line option.

The trick is that this option is not normally available; you need to set a registry key to enable it.

Enable the MSBuild Debugger

Under the HKLMSoftwareMicrosoftMSBuild4.0 key, create a string value called EnableDebugger with a value of “true”.

If you’re on a 64 bit system, you’ll also want to set the same value under the key HKLMSoftwareWow6432NodeMicrosoftMSBuild4.0.


If you then run msbuild /help, you should now see the documentation on the /debug switch:

                    Causes a debugger prompt to appear immediately so that
                    Visual Studio can be attached for you to debug the
                    MSBuild XML and any tasks and loggers it uses.


Now you can pass the /debug option to MSBuild when running it. This will immediately break into the debugger, which will usually give you a prompt to select your JIT debugger:


The debug session will then start at the very top of the root MSBuild project file, and you can go from there.

You can set breakpoints in your MSBuild project files from within the IDE, and inspect the MSBuild variables using Locals and Watch.

Some more tips:

  • Your breakpoints may not show up to be hit yet until the project file they’re contained in actually loads. If you continue on, the project will get loaded and the breakpoint will get hit.
  • To prevent yourself breaking into framework code that you don’t have source for, you can check the Enable Just My Code (Managed only) option under Debug > Options and Settings > Debugging > General.
  • From the Immediate window to evaluate conditions using EvaluateCondition:
Immediate input: EvaluateCondition("'$(MyProperty)' == ''")
Immediate output: false
  • From the Immediate window you can evaluate expressions using EvaluateExpression (remember to escape slashes):
Immediate input: EvaluateExpression("C:\$(MyFolderName)")
Immediate output: C:MyFolder

Original article and full details (recommended reading) is here:

Generating a type library for Visual Basic 6 ActiveX Components

When generating setup code or isolation code (for Side by Side assemblies and Registration-free COM), VB6 ActiveX Components can be a little troublesome.

ActiveX exes in particular can be difficult, with the WiX heat tool and various SxS tools not being able to harvest COM registration information from them properly.

A good way of avoiding these problems is to generate a type library (.tlb) from the VB6 component, and then pointing the code generation tools at the type library.

In VB6, you can generate a Type Library (.tlb) file for an ActiveX component:

  1. Project > <Project Name> Properties…
  2. Go to the Component tab
  3. Check Remote Server Files
  4. Click OK and build the project


You should now see a .tlb and .vbr file next to your binary.

The .vbr file is a text file containing registry information, which will be very helpful if the type library is still missing information you want to use for your isolation or installation authoring.


How To Make a Typelib (.TLB) File for ActiveX Components @ MSDN