fatal error C1084: Cannot read type library file: 'Smegui.tlb': Error loading type library/DLL.

Question

Hi,

I am trying to build an old version of an application which consists of VC++ projects that were written in Visual Studio 2003.

My OS is Windows 7 Enterprise (64-bit). When I try and build the solution I get the following errors:

• error C4772: #import referenced a type from a missing type library; '__missing_type__' used as a placeholder
• fatal error C1084: Cannot read type library file: 'Smegui.tlb': Error loading type library/DLL.

They both complain about the following import statement:

#import "Smegui.tlb" no_implementation

This is not a case of the file path being incorrect as renaming the Smegui.tlb file causes the compiler to throw another error saying it cannot find the library.

Smegui is from another application that this one depends on. I thought perhaps I was missing a dll but there is no such thing as Smegui.dll.

All I know about .tlb files is that they are a type library and you can create them from an assembly using tlbexp.exe or regasm.exe (the later also registers the assembly with COM)

There is also an Apache Ant build script which uses a custom task to invoke devenv.com to build the projects. This is the same script that the build server originally used to build the application. It gives me the same errors when I try and run it.

The strangest thing about this is that I knew it ought to work seeing as it is all freshly checked out from subversion. I tried many different combinations of admin vs user elevation, VS vs Ant build, cleaning, release.

I have got it to build successfully about 5 times but the build seems to be non-deterministic.

If anyone can shed some light on how this tlb stuff even works or what this error might mean I would greatly appreciate it.

Cheers,

Steiny

Answer 1

http://msdn.microsoft.com/en-us/library/sce74ah7%28VS.71%29.aspx

smegui.tlb is referencing some other tlb that the compiler can't find. If you have the .idl for smegui you might be able to figure out what the other is. I suspect the missing tlb is something that original build machine had registered but that your machine doesn't have registered.

A type library is a binary description of a set of interfaces, coclasses and enums. They're usually generated for COM components, in the case of tlbexp and regasm the tlb is created from the assembly metadata. For native COM components they are usually generated from an idl (Interface Description Language) file by the midl tool.

Edit:

I just noticed you're on x64 Windows. Are you building the project with a new version of Visual Studio? If so, are you targeting x86 or x64? If the latter, it may simply be a 32bit component that the compiler can't find (or less likely, a x64 component the x86 compiler can't find if you are targeting x86), for WOW64 the registry is virtualized for x86 vs. x64 applications.

Answer 2

Well I finally found out why I managed to get it to build sometimes and not others... sort of.

So long as I ran the build script with elevated administrator permissions and let that get as far as it could until that error occurred, then run the build script again as a protected administrator succeeded. Those steps must be done in that exact order with no other steps in between. If I try build in Visual Studio it does not work (although I did get it to succeed once). Probably some kind of virtualisation issue although it still doesn't quite make sense.

Well I don't need help on this any more and I know it's probably impossible to fully answer this question without knowing exactly what the build is doing. However if anyone does have any more thoughts I would happily receive them.

Cheers,

Steiny