janhq/jan · error · Error

Invalid backend archive name: ${archiveName}

Error message

Invalid backend archive name: ${archiveName}

What it means

Defensive check after the archive-name regex has matched: the version and backend capture groups must both be non-empty. If the regex matched structurally but produced empty captures for version or backend (edge case in the regex), this error fires.

Source

Thrown at extensions/llamacpp-extension/src/index.ts:2873

      !(await fs.existsSync(path)) ||
      (!path.endsWith('tar.gz') && !path.endsWith('zip'))
    ) {
      logger.error(`Invalid path or file ${path}`)
      throw new Error(`Invalid path or file ${path}`)
    }

    const match = re.exec(archiveName)

    if (!match) {
      throw new Error(
        `Failed to parse archive name: ${archiveName}. Expected format: [Optional prefix-]llama-<version>-bin-<backend>.(tar.gz|zip)`
      )
    }

    const [, prefix, version, backend] = match

    if (!version || !backend) {
      throw new Error(`Invalid backend archive name: ${archiveName}`)
    }

    // Include prefix in the backend identifier if present
    const backendIdentifier = prefix ? `${prefix}${backend}` : backend

    logger.info(
      `Detected prefix: ${prefix || 'none'}, version: ${version}, backend: ${backendIdentifier}`
    )

    const backendDir = await getBackendDir(backendIdentifier, version)

    try {
      await invoke('decompress', { path: path, outputDir: backendDir })
    } catch (e) {
      logger.error(`Failed to install: ${String(e)}`)
      throw new Error(`Failed to decompress archive: ${String(e)}`)
    }

View on GitHub (pinned to fad3f12a14)

Solutions

1. Rename the archive to follow the standard naming convention with explicit version and backend values.
2. If this fires on a correctly-named file, inspect the regex for a regression and verify the capture groups.

const BACKEND_ARCHIVE_RE = /^(.+?[-_])?llama(?:-main)?-(b\d+(?:-[a-f0-9]+)?)(?:-cudart-llama)?-bin-(.+?)\.(?:tar\.gz|zip)$/

function parseBackendArchive(name: string): { version: string; backend: string } | null {
  const m = BACKEND_ARCHIVE_RE.exec(name)
  if (!m || !m[2] || !m[3]) return null
  return { version: m[2], backend: m[3] }
}

// Before install:
const parsed = parseBackendArchive(archiveName)
if (!parsed) throw new Error('Cannot extract version and backend from archive name')

function hasVersionAndBackend(match: RegExpMatchArray | null): match is RegExpMatchArray {
  return !!match && !!match[2] && !!match[3]
}

When it happens

Trigger: An archive filename that technically satisfies the regex structure but has empty version or backend segments — this is rare given the regex requires non-empty patterns, but can occur with unexpected characters or a regex engine edge case.

Common situations: Extremely unusual filename constructions; regex was modified and introduced a bug allowing empty captures; an adversarial or corrupted filename.

Related errors

• Failed to parse archive name: ${archiveName}. Expected forma
• Invalid path or file ${path}
• Not a supported backend archive! Missing llama-server binary
• Invalid backend string: ${targetBackendString} supplied to u
• Invalid backend string format: "${targetBackendString}". Exp

AI-assisted analysis of janhq/jan@fad3f12a14 (2026-08-12). Data as JSON: /api/errors/453f2d1941db3fef. Report an issue: GitHub.