Internal error, please report upstream including the contents of _build/log.
Description:
  ("Invalid Module_name.t", { s = "03" })
Raised at Stdune__code_error.raise in file "src/stdune/code_error.ml", line
  9, characters 30-62
[...]
Called from Fiber.Execution_context.safe_run_k in file "src/fiber/fiber.ml",
  line 130, characters 8-11

I must not crash.  Uncertainty is the mind-killer. Exceptions are the
little-death that brings total obliteration.  I will fully express my cases. 
Execution will pass over me and through me.  And when it has gone past, I
will unwind the stack along its path.  Where the cases are handled there will
be nothing.  Only I will remain.