Backends & Resolution

shirabe drives any browser that speaks the Chrome DevTools Protocol — Google Chrome, Chromium, Microsoft Edge — through one CDP engine. Select one with SHIRABE_BACKEND:

ValueBackend
chrome (default in auto)Google Chrome
chromiumChromium
edgeMicrosoft Edge
auto (default)Try Chrome, then Chromium, then Edge

Resolution order

Whichever backend is chosen, shirabe resolves an executable in this order (mirroring ort's dependency model):

  1. 1
    Backend-specific override — CHROME_PATH / CHROMIUM_PATH / EDGE_PATH. If set, the path is authoritative; a missing path is a hard error.
  2. 2
    Build-time baked path — SHIRABE_BROWSER_PATH, emitted by build.rs when the `auto-fetch` feature downloads the pinned Chrome for Testing build into the shared cache during compilation.
  3. 3
    System binary on $PATH plus a handful of well-known install locations (`/usr/bin/google-chrome`, `/Applications/Google Chrome.app/...`, `C:\Program Files\Google\Chrome\Application\chrome.exe`, …).
  4. 4
    Runtime fetch (the runtime-fetch feature) — download the pinned Chrome for Testing build on first use into the cache.

Download knobs

The fetch step honours these environment variables, both at build time (build.rs) and at runtime:

EnvPurpose
SHIRABE_CHROME_VERSIONOverride the pinned Chrome for Testing version.
SHIRABE_CHROME_MIRRORDownload from a mirror (e.g. a GFW-friendly one) instead of the default Google host.
SHIRABE_CHROME_SHA256Optional hex checksum; the download is verified against it.
SHIRABE_DOWNLOAD_PROXYRoute the download through an http://, https:// or socks5:// proxy.
SHIRABE_DOWNLOAD_TIMEOUT_SECSPer-request timeout (default 600).
SHIRABE_SKIP_BROWSER_FETCHSkip both build-time and runtime downloads.

Because build.rs reads these too, a downstream crate can pin the whole toolchain in CI with one env: block.