Empty code coverage on transpiled JS code

I am inside a folder that has the below structure
src/ -> this has *.js and *.js.map
test/ -> this has *.js and *.js.map

I run the command c8@10.1.3/node_modules/c8/bin/c8.js --include src/**/*.js mocha@11.1.0/node_modules/mocha/bin/mocha.js test/unit/**/*.js --verbose

It does the tests but my coverage report says 0

----------|---------|----------|---------|---------|-------------------
File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files | 0 | 0 | 0 | 0 |
----------|---------|----------|---------|---------|-------------------

=============================== Coverage summary ===============================
Statements : Unknown% ( 0/0 )
Branches : Unknown% ( 0/0 )
Functions : Unknown% ( 0/0 )
Lines : Unknown% ( 0/0 )

I tried --src src as well. But nothing worked. Does C8 work for transpiled JS code? How do I debug the above problem?