Let's say you open up a new C codebase: What are its dependencies? You'll have to hunt through its README (hopefully it's up to date!), other build instructions, maybe CMake, maybe some custom build system, etc.

What version of dependencies does it use? If the code has been vendored, you at least know what code its using - but where do you look for updates to that code? Do you manually go out to wherever it was copied from now and then and look for updates? If the code isn't vendored, then how was it installed? From the package manager? If so, what operating system and version was used during development? If its not from a package, its might have been downloaded and installed manually? Again, where was it downloaded from? Where was it installed? What options did it use when it was compiled?

How do you handle transitive dependencies? Probably by hand. How well documented are they?

C suffers plenty of dependency issues.