Description

In src/infra/backup-create.ts, the writeTarArchiveWithRetry function attempts to clean up the temporary archive on failure using fs.rm at line 191:

await fs.rm(params.tempArchivePath, { force: true });

If the runTar process leaked an open file descriptor (which is common on Windows during failure), fs.rm will throw an EBUSY error. The error is caught, logged as a warning, and the retry loop continues without the file being removed.

When the next runTar attempt starts, it will try to write to params.tempArchivePath and immediately fail again because the file is still locked. This completely defeats the BACKUP_TAR_BACKOFF_MS mechanism, causing an immediate cascade of failures until BACKUP_TAR_MAX_ATTEMPTS is reached.

Location

src/infra/backup-create.ts

Impact

Backup creation can instantly fail on Windows instead of surviving temporary filesystem locks or IO contention via backoff.