linera-io/linera-protocol · error

GITHUB_PR_NUMBER is not set! This must be run from within CI

Error message

GITHUB_PR_NUMBER is not set! This must be run from within CI

What it means

In CI mode, GithubContext::from_env reads GITHUB_PR_NUMBER to identify the pull request; GitHub Actions sets it on pull_request events, and the tool treats its absence as 'not actually running in a PR CI context', failing fast.

Source

Thrown at linera-summary/src/github.rs:120

    }

    fn from_env(is_local: bool, pr_number: Option<u64>) -> Result<Self> {
        let env_pr_commit_hash = env::var("GITHUB_PR_COMMIT_HASH");
        let env_pr_branch = env::var("GITHUB_PR_BRANCH");
        let env_base_branch = env::var("GITHUB_BASE_BRANCH");
        let env_pr_number = env::var("GITHUB_PR_NUMBER");

        let (pr_commit_hash, pr_branch, base_branch, pr_number) = if is_local {
            let (commit_hash, branch_name, base) = Self::get_local_git_info()?;
            (
                commit_hash,
                branch_name,
                base,
                pr_number.ok_or_else(|| anyhow!("pr_number is None"))?,
            )
        } else {
            let pr_string = env_pr_number.map_err(|_| {
                anyhow!("GITHUB_PR_NUMBER is not set! This must be run from within CI")
            })?;
            (
                env_pr_commit_hash.map_err(|_| {
                    anyhow!("GITHUB_PR_COMMIT_HASH is not set! This must be run from within CI")
                })?,
                env_pr_branch.map_err(|_| {
                    anyhow!("GITHUB_PR_BRANCH is not set! This must be run from within CI")
                })?,
                env_base_branch.map_err(|_| {
                    anyhow!("GITHUB_BASE_BRANCH is not set! This must be run from within CI")
                })?,
                pr_string
                    .parse()
                    .map_err(|_| anyhow!("GITHUB_PR_NUMBER is not a valid number: {pr_string}"))?,
            )
        };

        Ok(Self {

View on GitHub (pinned to 6c226ddcb3)

Solutions

  1. Restrict the summary job to pull_request triggers in the workflow (if: github.event_name == 'pull_request')
  2. Or export a valid number: GITHUB_PR_NUMBER=42 with the other GITHUB_* variables
  3. Use pull_request_target/pull_request workflows where the variable is populated

Example fix

# before
on: [push, pull_request]
# after
on: [pull_request]
Defensive patterns

Strategy: validation

Validate before calling

#!/usr/bin/env bash
# Fail fast before running the summary step in CI mode
: "${GITHUB_PR_NUMBER:?GITHUB_PR_NUMBER is required; run under a pull_request workflow}"

Try / catch

if let Err(e) = Github::new(false, None) {
    if e.to_string().contains("GITHUB_PR_NUMBER") {
        eprintln!("no PR context; restrict this job to pull_request events");
    }
    return Err(e.into());
}

Prevention

When it happens

Trigger: Running the summary workflow on a push event or workflow_dispatch (no PR context), or outside GitHub Actions without exporting the variable.

Common situations: Adding the summary step to a workflow whose triggers include push; manual workflow_dispatch runs; runners with a minimal environment.

Understand the failure class

Background: "environment variable is not set" and "Missing keys in environment" errors: what missing required env var messages mean and how to fix them — this error's family across 28 libraries.

Related errors

AI-assisted analysis of linera-io/linera-protocol@6c226ddcb3 (2026-08-22). Data as JSON: /api/errors/24eb1e5f31156827. Report an issue: GitHub.