Puppeteer: Failed to download bisect-builds.py: {value}

The bisect helper could not download bisect-builds.py.

Error message

Failed to download bisect-builds.py: {value}

{value} is replaced by the value shown in your error message.

How this error happens

The experimental browser bisector downloads its Python helper before running a regression test. A non-success response from that helper’s host stops setup.

The commands illustrate a project that intentionally uses browser bisection; no helper or test is supplied by this website.

npx @puppeteer/browsers bisect smoke \
    --good="$GOOD_CHROME_BUILD" \
    --bad="$BAD_CHROME_BUILD"

How to fix

For a download failure, restore trusted network access to the helper’s host. For a child-process failure, inspect its stderr, ensure the required runtime is present, and verify the smoke test before rerunning.

npm run smoke

npx @puppeteer/browsers bisect smoke \
    --good="$GOOD_CHROME_BUILD" \
    --bad="$BAD_CHROME_BUILD"

Things to keep in mind

This assumes your own project already has a smoke test and the environment variables contain valid Chrome build identifiers. The bisector downloads and runs a helper; it is not required for ordinary Puppeteer automation. A smoke test failure alone is not proof that the helper subprocess emitted this message.

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