Function write_bundle 

pub(crate) fn write_bundle(
    dir: &Path,
    arenas: Vec<CallTraceArena>,
    recordings: Vec<DebugRecording>,
    contract_names: &[Vec<Option<String>>],
    sources: &ContractSources,
    known_contracts: &ContractsByArtifact,
) -> Result<()>

Writes a bundle that soldb’s own tools read, for example soldb profile --trace-file <dir>/trace.json --contracts <dir>/contracts.json.

The bundle holds the transaction trace, a contracts mapping, one combined.json per contract address with the legacy source maps and bytecode solc --combined-json writes, and the sources under their project paths, where soldb looks for them.