How to run tests only in rust file that belongs to PyO3 package?

Question

I have a Rust package which is basically a PyO3 extension. In there I have two files, lib.rs, that is creating a python module and doing conversions from and into Rust types, and parsing.rs which is pure Rust code that I'm wrapping. Now the issue I have is running tests where I only want to run unit tests inside parsing.rs.

When I run cargo test src\parsing.rs I get an error

my_repo\my_package>cargo test src\parsing.rs
   Compiling pyo3-build-config v0.17.3
error: failed to run custom build command for `pyo3-build-config v0.17.3`                                                                                   
                                                                                                                                                            
Caused by:                                                                                                                                                  
  process didn't exit successfully: `my_repo\target\debug\build\pyo3-build-config-f455835126268765\build-script-build` (exit code: 1)
  --- stdout                                                                                                                                                
  cargo:rerun-if-env-changed=PYO3_CONFIG_FILE                                                                                                               
  cargo:rerun-if-env-changed=PYO3_NO_PYTHON                                                                                                                 
  cargo:rerun-if-env-changed=PYO3_PYTHON                                                                                                                    
  cargo:rerun-if-env-changed=VIRTUAL_ENV                                                                                                                    
  cargo:rerun-if-env-changed=CONDA_PREFIX                                                                                                                   
  cargo:rerun-if-env-changed=PATH                                                                                                                           
                                                                                                                                                            
  --- stderr                                                                                                                                                
  error: no Python 3.x interpreter found                                                                                                                    

my_repo\my_package>

So my question is how to run unit tests only inside parsing.rs without triggering anything related to python? For building the whole package, I have a complex setup which uses cmake instead of maturin, so that's why I'm targeting only one file.