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Turn Nix build logs into JUnit XML reports for your CI.

Features

• Translate: Pipe any Nix build output into JUnit XML
• Build: Run nix build and get JUnit XML in one command
• Check: Discover and run all flake checks, producing a single JUnit report
• CI-ready: Works with GitLab CI, Jenkins, GitHub Actions, and any JUnit-compatible system
• Verbose logging: Control Nix log verbosity to capture the right level of detail
• Colored output: Human-readable summary with color-coded pass/fail/cached status

Quick Example

# Pipe nix build output into junix
nix build --log-format internal-json -v --print-build-logs --no-link .#pkg1 |& junix translate -o result.xml

# Or let junix drive the build
junix build .#pkg1 .#pkg2

# Or check all flake checks
junix check

Example output

When you run junix check on a flake with passing and failing checks, you get a colorful summary on stderr:

$ junix check ./tests/sample-flake
eval aarch64-linux ... 2 checks
  ✓ nix eval ./tests/sample-flake#checks.aarch64-linux.failing
  ✓ nix eval ./tests/sample-flake#checks.aarch64-linux.passing
eval x86_64-linux ... 2 checks
  ✓ nix eval ./tests/sample-flake#checks.x86_64-linux.failing
  ✓ nix eval ./tests/sample-flake#checks.x86_64-linux.passing
build x86_64-linux ... 2 checks
  ✗ nix build ./tests/sample-flake#checks.x86_64-linux.failing
  ✓ nix build ./tests/sample-flake#checks.x86_64-linux.passing (cached)

FAILED (0/4 evals, 1/2 builds)

And a JUnit XML report on stdout (or to a file with -o):

<?xml version="1.0" encoding="utf-8" ?>
<testsuites>
    <testsuite
        name="nix-eval.aarch64-linux"
        tests="2"
        failures="0"
        errors="0"
        skipped="0"
        time="0"
    >
        <testcase
            name="nix eval ./tests/sample-flake#checks.aarch64-linux.failing"
            classname="eval checks.aarch64-linux.failing"
            time="0"
        >
            <system-out>
                /nix/store/bfhm668k31wxqhgzwd1knnnlzh8rpsxc-failing-check.drv
            </system-out>
        </testcase>
        <testcase
            name="nix eval ./tests/sample-flake#checks.aarch64-linux.passing"
            classname="eval checks.aarch64-linux.passing"
            time="0"
        >
            <system-out>
                /nix/store/132yfmn5jsgxxdqmqgbcl5nf05k2203z-passing-check.drv
            </system-out>
        </testcase>
    </testsuite>
    <testsuite
        name="nix-eval.x86_64-linux"
        tests="2"
        failures="0"
        errors="0"
        skipped="0"
        time="0"
    >
        <testcase
            name="nix eval ./tests/sample-flake#checks.x86_64-linux.failing"
            classname="eval checks.x86_64-linux.failing"
            time="0"
        >
            <system-out>
                /nix/store/8lsmx09idfa0dmyg7d03wzic50whi4x3-failing-check.drv
            </system-out>
        </testcase>
        <testcase
            name="nix eval ./tests/sample-flake#checks.x86_64-linux.passing"
            classname="eval checks.x86_64-linux.passing"
            time="0"
        >
            <system-out>
                /nix/store/z203q28202sj879rz2b36c2bnxb95x1q-passing-check.drv
            </system-out>
        </testcase>
    </testsuite>
    <testsuite
        name="nix-build.x86_64-linux"
        tests="2"
        failures="1"
        errors="0"
        skipped="1"
        time="0"
    >
        <testcase
            name="nix build ./tests/sample-flake#checks.x86_64-linux.failing"
            classname="/nix/store/8lsmx09idfa0dmyg7d03wzic50whi4x3-failing-check.drv"
            time="0"
        >
            <failure message="Build failed" type="failure" />
            <system-out>This check fails</system-out>
            <system-err
            >error: Cannot build '/nix/store/8lsmx09idfa0dmyg7d03wzic50whi4x3-failing-check.drv'.
       Reason: builder failed with exit code 1.
       Output paths:
         /nix/store/zxa2hj58grdp2j5bmnywznqwnx66qn6m-failing-check
       Last 1 log lines:
       &gt; This check fails
       For full logs, run:
         nix log /nix/store/8lsmx09idfa0dmyg7d03wzic50whi4x3-failing-check.drv
</system-err>
        </testcase>
        <testcase
            name="nix build ./tests/sample-flake#checks.x86_64-linux.passing"
            classname="checks.x86_64-linux.passing"
            time="0"
        >
            <skipped message="Cached / substituted" type="cached" />
        </testcase>
    </testsuite>
</testsuites>

Installation

pipx install junix
# or
uv tool install junix
# or
nix profile install gitlab:moduon/junix

Credits

Junix is developed and maintained by Moduon. Need a professional Nix or Odoo partner? Contact us.