What might cause MSBuild to behave differently from machine-to-machine?

Question

I have a C# program (not ASP.NET or even web-related) with platform AnyCPU targeting .NET v3.5 that references a 32-bit third-party .dll. Unfortunately, I also have several "work of art" build machines in our CI pipeline that build this program. I'm trying to add another one but I can't figure out what allows it to build.

Whenever I try to build on this new machine, I get

LC : error LC0000: 'Could not load file or assembly 'ASSEMBLY' or one of its dependencies. An attempt was made to load a program with an incorrect format.'

So far my only lead is that someone's installed several unneeded programs (visual studio 2010, several C++ runtimes, Windows SDK, etc) but those shouldn't break my build and I don't want to uninstall things willy nilly.

Here is the command which works on my old build machine and fails on my new one:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\MSBuild.exe /property:Configuration=release;Platform=AnyCPU;TargetFrameworkVersion=v3.5 Utilities\UtilityGUI\UtilityGUI.csproj

If I change the Platform property to x86 it works on both machines. Changing it to x64 breaks it on both machines.

What could be causing this? I checked msbuild.exe.config on the machines and compared the registry under SOFTWARE/Microsoft/VisualStudio as well as SOFTWARE/Microsoft/MSBuild . I don't want to change code as it works on my other machines and branches that haven't had a merge yet couldn't build on this machine.

Answer 1

The problem is with your 32-bit reference. You can't load a 32-bit assembly into a 64-bit process. Is there a reason why you can't target x86 exclusively?

As for why it's building on one machine and not the other, it may be that the AnyCPU profile on one machine is set to prefer 32-bit, or it may be that the machine that's successfully building is actually a 32-bit machine and is targeting x86 out of necessity. Either way, you won't be able to produce x64 builds when referencing a 32-bit dll.