How to Debug Linking Errors in Rust

Linking errors in Rust often occur when the compiler cannot find external dependencies or library paths, especially in complex setups like mdbook testing. To fix this, explicitly pass the compiled dependency path using the --library-path flag when running tests. For the trpl crate in this repository, build the crate first, then run the test command with the correct path to the debug dependencies.

cd packages/trpl
cargo build
mdbook test --library-path packages/trpl/target/debug/deps

Linking errors happen when the program builder can't find the pieces it needs to put the final program together. It is like trying to assemble a puzzle but missing the box with the picture on it. You fix it by telling the builder exactly where to look for those missing pieces.