Write message for `todo!` macro by moreal · Pull Request #5504 · RustPython/RustPython

moreal

This pull request writes messages for todo! macros to help debugging.

For example, I met a situation that I cannot know lines where the build fails, when working on #5486.

error: proc macro panicked
  --> pylib/src/lib.rs:14:5
   |
14 |     rustpython_derive::py_freeze!(dir = "./Lib", crate_name = "rustpython_compiler_core");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: not yet implemented

After this pull request, I met a helpful message:

error: proc macro panicked
  --> pylib/src/lib.rs:14:5
   |
14 |     rustpython_derive::py_freeze!(dir = "./Lib", crate_name = "rustpython_compiler_core");
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: not yet implemented: implement SymbolTableBuilder::scan_type_params TypeParam:::ParamSpec