let mut file = tokio::fs::File::create(&cache_path)

                    let tmp = cache_path.with_extension("tmp");
                    let mut file = tokio::fs::File::create(&tmp)

                        .with_context(context("writing", &cache_path))?;

                        .with_context(context("writing", &tmp))?;

                    drop(file);
                    tokio::fs::rename(tmp, &cache_path).await?;