Function write_built_file_with_opts 

pub fn write_built_file_with_opts(
    manifest_location: Option<&Path>,
    dst: &Path,
) -> Result<()>

Writes rust-code describing the crate at manifest_location to a new file named dst.

Errors

The function returns an error if the file at dst already exists or can’t be written to. This should not be a concern if the filename points to OUR_DIR.