cargo-nextest

A guide for generating Trunk-compatible test reports for Rust

You can automatically detect and manage flaky tests in your Rust projects by integrating with Trunk. This document explains how to configure cargo-nextest to output JUnit XML reports that can be uploaded to Trunk for analysis.

Checklist

By the end of this guide, you should achieve the following before proceeding to the next steps to configure your CI provider.

Generate a compatible test report
Configure the report file path or glob
Disable retries for better detection accuracy
Test uploads locally

After correctly generating reports following the above steps, you'll be ready to move on to the next steps to configure uploads in CI.

Generating Reports

cargo-nextest has built-in reporting for JUnit XML reports, which is trunk-compatible. You can enable JUnit reporting by adding the following to your nextest config:

.config/nextest.toml

[profile.ci.junit]
path = "junit.xml"

You can invoke this profile when running tests with:

cargo nextest run --profile ci

Report File Path

cargo-nextest outputs artifacts at target/nextest by default. When you provide a profile and a file name via the config example above, it produces a report at target/nextest/ci/junit.xml.

Disable Retries

You need to disable automatic retries if you previously enabled them. Retries compromise the accurate detection of flaky tests.

Omit the --retries option.

Try It Locally

The Validate Command

You can validate your test reports using the Trunk CLI. If you don't have it installed already, you can install and run the validate command like this:

curl -fsSLO --retry 3 https://trunk.io/releases/trunk && chmod +x trunk
./trunk flakytests validate --junit-paths "./target/nextest/ci/junit.xml"

This will not upload anything to Trunk. To improve detection accuracy, you should address all errors and warnings before proceeding to the next steps.

Test Upload

Before modifying your CI jobs to automatically upload test results to Trunk, try uploading a single test run manually.

You make an upload to Trunk using the following command:

curl -fsSLO --retry 3 https://trunk.io/releases/trunk && chmod +x trunk
./trunk flakytests upload --junit-paths "./target/nextest/ci/junit.xml" \
    --org-url-slug <TRUNK_ORG_SLUG> \
    --token <TRUNK_ORG_TOKEN>