What causes "Property is not set" in SonarSource/sonarqube?

Define the path property in conf/sonar.properties (e.g. sonar.path.home=/opt/sonarqube).

SonarSource/sonarqube · error · IllegalArgumentException

Property is not set

Error message

Property  is not set

What it means

Props.nonNullValueAsFile resolves a property to a java.io.File and throws IllegalArgumentException when the property is not set at all (null). Unlike File handling errors, this fires purely on a missing configuration value, before any filesystem access.

Solutions

Define the path property in conf/sonar.properties (e.g. sonar.path.home=/opt/sonarqube).
Verify the property key name against the version's documentation, since path keys changed between versions.
Use valueAsFile-style lookup with a default if the path can be derived (e.g. relative to the installation root).

Example fix

// before
File home = props.nonNullValueAsFile("sonar.path.home");
// after
File home = new File(props.nonNullValue("sonar.path.data")).getParentFile(); // or set sonar.path.home in sonar.properties

Defensive patterns

Strategy: validation

Validate before calling

if (props.value("sonar.path.home") == null) {
  throw new IllegalStateException("sonar.path.home is not set; cannot resolve installation paths");
}

Try / catch

try {
  File home = props.nonNullValueAsFile("sonar.path.home");
} catch (IllegalArgumentException e) {
  logger.error("Path property not configured: {}", e.getMessage());
}

Prevention

Set all sonar.path.* properties explicitly in conf/sonar.properties.
After unpacking a distribution, never delete or rename the conf directory.
Document which JDBC driver path properties your database flavor requires.

When it happens

Trigger: Calling props.nonNullValueAsFile("sonar.path.home") (or data/log paths, or JDBC driver path for oracle/h2/postgresql via checkAndComplete) when the key is absent from the properties.

Common situations: Unpacked SonarQube distribution without conf/sonar.properties populated; JDBC driver path property expected but never set; tests building Props without path defaults.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

AI-assisted analysis of SonarSource/sonarqube@184c821202 (2026-09-09). Data as JSON: /api/errors/b6d626493e0ddc3b. Report an issue: GitHub.

Appendix: source

Thrown at server/sonar-process/src/main/java/org/sonar/process/Props.java:82

  public String value(String key, @Nullable String defaultValue) {
    String s = value(key);
    return s == null ? defaultValue : s;
  }

  public boolean valueAsBoolean(String key) {
    String s = value(key);
    return s != null && Boolean.parseBoolean(s);
  }

  public boolean valueAsBoolean(String key, boolean defaultValue) {
    String s = value(key);
    return s != null ? Boolean.parseBoolean(s) : defaultValue;
  }

  public File nonNullValueAsFile(String key) {
    String s = value(key);
    if (s == null) {
      throw new IllegalArgumentException("Property " + key + " is not set");
    }
    return new File(s);
  }

  @CheckForNull
  public Integer valueAsInt(String key) {
    String s = value(key);
    if (s != null && !"".equals(s)) {
      try {
        return Integer.parseInt(s);
      } catch (NumberFormatException e) {
        throw new IllegalStateException("Value of property " + key + " is not an integer: " + s, e);
      }
    }
    return null;
  }

  public int valueAsInt(String key, int defaultValue) {

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