The following package names could not be resolved: in manifest but not in project

I am getting weird errors with ChainRules in Julia 1.8

To try to fix the problem, I went into the package manager for my project, and tried both rm ChainRules and rm Zygote. Both times I got the following error message:

ERROR: The following package names could not be resolved:
 * Name (UUID in manifest but not in project)

Just to check my understanding, I think that is because the only package I’m really downloading in Project.toml is Flux, which then has dependencies in Zygote and ChainRules, and those dependencies are noted in Manifest.toml but not in Project.toml

Does this seem like a correct understanding of what is going on?

Yes.

The text could certainly be clearer here, but the message is that rm is for dealing with direct dependencies of your project, but Pkg could only find this package (ChainRules/Zygote) in Manifest.toml.