openzipkin/zipkin · error · IllegalStateException

Missing :

Error message

Missing :

What it means

DependencyLink.Builder.build throws IllegalStateException('Missing : parent child') when build() runs without both parent and child having been set. This is the deferred counterpart to the per-field NPEs: if the builder was constructed from a source or manipulated directly, the missing fields are only detected at build time, and the message lists exactly which fields are absent.

Solutions

1. Set both parent and child before build().
2. Validate inputs up front and skip/pad the link when a name is missing.
3. Add a unit test asserting links built from your aggregation always have both names.

Example fix

// before
DependencyLink link = DependencyLink.newBuilder().parent("frontend").callCount(2).build();

// after
DependencyLink link = DependencyLink.newBuilder().parent("frontend").child("backend").callCount(2).build();

if (parent == null || child == null) throw new IllegalStateException("link incomplete: parent=" + parent + ", child=" + child);
DependencyLink link = DependencyLink.newBuilder().parent(parent).child(child).build();

When it happens

Trigger: Calling build() after newBuilder() with only parent(...) set (or neither field), or constructing a Builder from a DependencyLink whose fields were somehow cleared.

Common situations: Copy-paste builders that set the same field twice; conditional code that skips child(...) in an edge case; data-driven link construction where one side's key is absent from input.

Related errors

• child == null
• parent == null
• Missing :
• Already Executed
• clientProps is empty

AI-assisted analysis of openzipkin/zipkin@878ce2a1fa (2026-08-14). Data as JSON: /api/errors/062d6a05ac72c3c5. Report an issue: GitHub.

Appendix: source

Thrown at zipkin/src/main/java/zipkin2/DependencyLink.java:96

    }

    /** @see #callCount() */
    public Builder callCount(long callCount) {
      this.callCount = callCount;
      return this;
    }

    /** @see #errorCount() */
    public Builder errorCount(long errorCount) {
      this.errorCount = errorCount;
      return this;
    }

    public DependencyLink build() {
      String missing = "";
      if (parent == null) missing += " parent";
      if (child == null) missing += " child";
      if (!missing.isEmpty()) throw new IllegalStateException("Missing :" + missing);
      return new DependencyLink(this);
    }
  }

  @Override public String toString() {
    return new String(DependencyLinkBytesEncoder.JSON_V1.encode(this), UTF_8);
  }

  // clutter below mainly due to difficulty working with Kryo which cannot handle AutoValue subclass
  // See https://github.com/openzipkin/zipkin/issues/1879
  final String parent, child;
  final long callCount, errorCount;

  DependencyLink(Builder builder) {
    parent = builder.parent;
    child = builder.child;
    callCount = builder.callCount;
    errorCount = builder.errorCount;

View on GitHub (pinned to 878ce2a1fa)