If you're fluent in Rust, you will have no problem learning C considered as a language. If C has any faults it is that it is too simple. Rust even sensitizes you nicely to the worst pokey bits of C, so you won't be wandering blind through the landscape of memory safety like most people learning C. I don't think you'd need books or anything, just grab some tutorials online and start banging away. It's not a hard langu…
Agreed. This is what's prevented me from learning C by contributing to large projects. I've always had trouble understanding the dependency management and build system of every project, as it seems everyone does it differently.
I kinda wish someone made a "C/C++ for Rust Developers", "CMake for the Rest of Us", or similar text that focuses enough on dep management and build systems.