GuidesTroubleshooting
Ferry cannot detect the runtime
The build finds no file that tells Ferry how to build the app.
What you see
could not detect the runtime: add a Dockerfile, or a package.json, requirements.txt, pyproject.toml, Pipfile, go.mod, Cargo.toml, Gemfile or index.html, or set the runtime explicitlyThe deploy gets the status build_failed. The live deploy continues to answer.
Why it occurs
The build context has no file that tells Ferry how to build the app. Ferry finds the runtime from these files.
How to repair it
| Case | Repair |
|---|---|
| The file is not there | Add a Dockerfile, or the project file of your language (package.json, go.mod, …). |
| The app is in a subdirectory | Set --root-dir. |
| You know the runtime | Set --runtime. |
See Builds & runtimes.