Package installation failure

What this failure means

The dependency installation step failed because the requested package or version could not be found in the configured registry, package index, or OS repository.

Symptoms

Faultline looks for one or more of these log fragments:

npm ERR! code E404
npm ERR! 404 Not Found
could not find package
package not found
apt-get install failed
dpkg: error
E: Unable to locate package

Diagnosis

The dependency installation step failed because the requested package or version could not be found in the configured registry, package index, or OS repository.

This usually means the package name is wrong, the version constraint points at an unpublished release, or CI is configured to use a repository mirror that does not contain the requested artifact.

Fix steps

1. Re-run the exact install command locally with verbose logging from the same package manager, so you can see which package name, version, or index URL failed.
2. Check that the package name and requested version actually exist in the configured registry or package index using that package manager’s own metadata lookup command, such as npm view, pip index versions, or apt-cache policy.
3. If the package is private, verify the registry configuration files are present before the install step runs, for example .npmrc, pip.conf, or the apt sources list used by the job.
4. If a package was removed or renamed, pin to a known-good published version or replace it with the maintained package.
5. If CI uses a mirror or proxy, confirm the missing version has been synced there before retrying the build.

Validation

• Run a registry metadata check for the missing package or version.
• Re-run the failing install command.
• Confirm CI proceeds past dependency installation without the original package-not-found signature.

Why it matters

Dependency installation is part of the build boundary. When CI cannot resolve the exact package set, later compile and test failures are noise rather than the root cause.

Prevention

• Keep dependency versions pinned in a lockfile or constraints file.
• Mirror critical internal and third-party packages in a registry you control.
• Keep registry bootstrap and auth wiring in a shared CI template so package source settings do not drift between pipelines.

Try it locally

npm view <package>@<version>
pip index versions <package>
apt-cache policy <package>
npm install
pip install -r requirements.txt

How Faultline detects it

Use faultline explain install-failure to see the full playbook.

faultline analyze build.log
faultline explain install-failure

Generated from playbooks/bundled/log/build/install-failure.yaml. Do not edit directly.