Azure Functions Core Tools "func: command not found" in CI

The step invoked func (Azure Functions Core Tools) but the runner has no such executable on PATH. Core Tools is a separate install and is not present on most base images by default.

What this error means

A step running func start, func host start, or func azure functionapp publish fails with "func: command not found" and exit code 127.

/home/runner/work/_temp/script.sh: line 1: func: command not found
Error: Process completed with exit code 127.

Common causes

Core Tools is not installed on the runner

The image does not ship Azure Functions Core Tools, and no install step ran before the func command.

Installed but not on PATH

A local npm install placed func under node_modules/.bin, which is not on PATH for a bare func call.

How to fix it

Install Core Tools before using func

1. Install Azure Functions Core Tools v4 in a setup step.
2. Confirm func --version prints a 4.x version.
3. Run your func command after the install.

npm install -g azure-functions-core-tools@4 --unsafe-perm true
func --version

Call the local binary explicitly

If installed as a project dependency, invoke it through npx or the bin path.

npx func host start

How to prevent it

• Install Core Tools v4 as an explicit CI step.
• Verify func --version before invoking the host.
• Prefer npx for project-local Core Tools installs.

Related guides