Debug Rust macros by using rustc flags or RUSTFLAGS to expand and inspect the generated code before compilation.
Debug Rust macros by enabling verbose expansion output to inspect the generated code before compilation. Run the following command to expand macros and view the resulting code in the terminal:
rustc -Z macro-backtrace --pretty=expanded your_file.rs
If you are using Cargo, add the RUSTFLAGS environment variable to see macro expansions during the build process:
RUSTFLAGS="-Z macro-backtrace" cargo build
Macros generate code automatically before your program runs, which can hide errors deep inside the expansion. Debugging them is like looking at the blueprint of a house before the walls are built to see where the design went wrong. This process reveals the hidden code so you can spot syntax errors or logic mistakes that the compiler is complaining about.