Break the Build: What It Is, Causes, and How to Avoid It in Your Project

What Is Breaking the Build in Development

Breaking the build is a situation where after introducing changes, the project stops building. In the context of CI/CD, this means the build pipeline fails and no artifact is created.

In the world of mobile and web development, a build is the process of translating source code into an executable file or package. For Android, it’s building an APK or AAB via Gradle; for iOS, compiling via Xcode; for web projects, bundling via Webpack or Vite. You can break the build at any of these stages.

Modern version control systems and CI/CD tools like Jenkins, GitHub Actions, and GitLab CI automatically detect a broken build and notify the team. Most projects have a rule: if the build is broken, the priority of all other tasks is lowered until the build is fixed.

fun main() {
    val message: String = "Build successful"
    println(message)
    
    // This line breaks the build
    val number: Int = "not a number"
}

In this example, assigning a string to a variable of type Int causes a compilation error. Type mismatch is one of the most common causes of a broken build in statically typed languages.

Main Causes of Build Failure

There are several categories of errors that lead to a broken build. According to GitLab analytics for 2024, the distribution of causes is as follows.

The most insidious category is dependency issues. Updating a library in one module can break the build in a neighboring module if the API or method behavior changes.

Syntax errors, on the other hand, are detected quickly — the compiler points to the exact line and error type. This is why statically typed languages are considered more reliable in terms of build stability than dynamically typed ones.

How a Broken Build Affects the Team

A broken build directly impacts team productivity. When the build fails, developers cannot get the latest version of the project from the repository, and the CI pipeline is blocked for all subsequent changes.

An Atlassian study from 2023 showed that projects where the build remains broken for more than four hours lose an average of 25% of the team’s productive time. Developers are forced to divert their attention to diagnosing the problem instead of completing their tasks.

In addition to productivity, team morale also suffers. The developer who broke the build experiences pressure from colleagues. In healthy teams, the rule is: do not punish for a broken build, but require an immediate fix. Blameless culture is an approach where the incident is analyzed as a systemic problem rather than someone’s mistake.

In distributed teams, a broken build can block colleagues in another time zone. If a developer from Europe breaks the build before leaving, the team in Asia may lose an entire working day waiting for the fix.

How to Prevent a Broken Build

Preventing a broken build starts with local checks before committing. Every developer should run tests and a build before pushing changes. The main prevention methods are divided into several levels.

• Pre-commit hooks — automatic checks before creating a commit, including linters and formatters
• Local build — running compilation before pushing, especially for statically typed languages
• Unit tests — covering key modules with tests for early regression detection
• Code review — having a colleague review changes before merging into the main branch

The second level is CI/CD pipeline configuration. Each Pull Request must pass automatic build and testing before merging. If the build fails, the PR is blocked until fixed. This approach is called gated commit and is used in most modern projects.

The third level is monitoring and statistics. Teams track the Mean Time To Repair (MTTR) metric. The lower this indicator, the faster the team responds to a broken build. The target value is no more than 30 minutes.

What to Do If the Build Is Broken

When the build is broken, the first step is to identify which developer last made changes. Git provides the git bisect tool, which allows you to find the commit that broke the build through binary search.

# Start bisect with known good and bad commits
git bisect start
git bisect bad HEAD
git bisect good abc1234

# Git checks out a commit in the middle
# Build and test, then mark:
git bisect good  # if build passes
git bisect bad   # if build fails

# After ~log2(n) steps, git shows the culprit
git bisect reset

After finding the problematic commit, there are two possible courses of action. The first is to revert changes using git revert if the fix requires time. This is the safest approach, especially when the build blocks the entire team.

The second option is an immediate fix with a new commit. This approach is preferable if the problem is local and clear. After the fix, push the changes and confirm the build passes. In any case, the build recovery time should not exceed one hour.