One my project has leading uppercase latter in crate name
Even it works already with few additional libraries, I want make one more application-wide lib crate for some shared features, for all app members. But found that can't use local lib.rs crate, because project has uppercase later in the name.
What should I do now: rename project to lowercase or just create new separated library crate again?
You can just add a src/lib.rs file to your existing project, put your shared code in there and use it in your binary crates, all within the same package. No need to create a new package for this. When importing from the library in your binary crates, you are going to see a warning though, because your library does not adhere to the standard naming rules for crates, namely snake_case or kebab-case. You can override the name of your library crate in your manifest file (Cargo.toml) to fix this:
[lib]
name = "yoda"
Then you can just use yoda::*; to import stuff from it in your src/main.rs or other binaries you want to add.
Useful links if you want to explore how Cargo targets work in more details:
So I can just define the name for [lib] separately from main project name, that's cool
because, it's my first crate and was worried the letters case does not follow standards to use it as the library also.