Package installation failure

April 30, 2026 · View on GitHub

Playbook ID: install-failure Category: build Severity: high Tags: install, dependencies, npm, pip, apt

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.

Common log signals

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This usually means the package name is wrong, the version constraint points at an unpublished release, or CI is configured to use a repository mirror that does not contain the requested artifact.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

Likely files to inspect

  • package.json
  • package-lock.json
  • requirements.txt
  • pyproject.toml
  • .npmrc
  • pip.conf

Run Faultline

faultline analyze build.log
faultline explain install-failure
faultline workflow build.log --json --mode agent

Search phrases this page answers

  • Package installation failure
  • Build: package installation failure
  • E: Unable to locate package
  • GitHub Actions package installation failure
  • faultline explain install-failure
  • npm package installation failure

Generated from playbooks/bundled/log/build/install-failure.yaml. Do not edit directly — run make docs-generate.