When you are trying to get #codeanalysis working for a real old #project. Said project uses a tool to incorrectly generate vxproj files and hundreds of them, all use same #guid that subtly breaks things. You find that there is a tool that does that. Written in #visualbasicnet that no one have touched in 10 years. You also find out that this tool is used in many projects. And each repo has its own copy of it. So you manually need to update about 50 repos... *cries in #LegacyCode*