GitLab CI Artifact Upload Error Fix

In this tutorial, you'll learn about GitLab CI Artifact Upload Error Fix. We cover key concepts, practical examples, and best practices.

Your GitLab CI job fails with Uploading artifacts to coordinator... error — the artifact file path is wrong, the file is too large, or the runner has no storage configured.

The Problem

# WRONG — artifact path that doesn't exist
build:
  script:
    - mkdir -p dist
    - echo "built" > dist/app.js
  artifacts:
    paths:
      - dist/app.min.js

Uploading artifacts to coordinator... error
FATAL: invalid argument

The pipeline creates dist/app.js but the artifact path specifies dist/app.min.js. GitLab CI checks if the path exists before uploading — if it doesn't, the job fails with an upload error.

Step-by-Step Fix

1. Match artifact paths to actual files

build:
  script:
    - npm run build
  artifacts:
    paths:
      - dist/
    expire_in: 1 week

2. Set artifact size limits

build:
  artifacts:
    paths:
      - dist/
    reports:
      junit: test-results/**/junit.xml
    expire_in: 30 days

pages:
  script:
    - mv public/ public_html/
  artifacts:
    paths:
      - public_html

GitLab has a default artifact size limit (varies by plan — typically 100MB-1GB). Set expire_in to auto-delete artifacts after a period.

3. Pass artifacts between jobs

build:
  stage: build
  artifacts:
    paths:
      - dist/
    expire_in: 1 hour

test:
  stage: test
  needs: [build]
  script:
    - ls dist/
    - npm run test

4. Use reports for test results

test:
  artifacts:
    reports:
      junit: test-results/junit.xml
      coverage_report:
        coverage_format: cobertura
        path: coverage/cobertura-coverage.xml

Expected output:

Uploading artifacts...
dist/: found 15 files
Uploading artifacts to coordinator... ok
Job succeeded

Prevention Tips

• Verify artifact paths exist in the build directory
• Use directories (dist/) instead of individual files
• Set expire_in to manage storage costs
• Use needs: for explicit job dependencies
• Check the project's artifact size limit in Settings > CI/CD

Common Mistakes with ci artifact

1. Forgetting deriving (Show, Eq) on custom data types needed for debugging
2. Placing the wildcard pattern first in case expressions, making all subsequent patterns unreachable
3. Using head and tail instead of pattern matching, causing runtime errors on empty lists

These mistakes appear frequently in real-world GITLAB code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

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