An sbt plugin for missinglink.

Add the following lines in project/plugins.sbt:

addSbtPlugin("ch.epfl.scala" % "sbt-missinglink" % "<sbt-missinglink-version>")
libraryDependencies ++= List(
  "com.spotify" % "missinglink-core" % "<missinglink-core-version>",
  "org.ow2.asm" % "asm-tree" % "<asm-tree-version>",
)

You can find the latest missinglink-core version in their release list.

sbt-missinglink	missinglink-core	asm-tree

Then, run the following task for the project you want to test:

> theProject/missinglinkCheck

This will check that the transitive dependencies of your project do not exhibit any binary compatibility conflict, assuming that the methods of your Compile configuration (in src/main/) are all called.

You can test another configuration, such as Test or Runtime, with:

> theProject/Runtime/missinglinkCheck

By default, the plugin fails the build if any conflicts are found. It can be disabled by the missinglinkFailOnConflicts setting:

missinglinkFailOnConflicts := false

Conflicts can be ignored based on the package name of the class that has the conflict. There are separate configuration options for ignoring conflicts on the "source" side of the conflict and the "destination" side of the conflict. Packages on the source side can be ignored with missinglinkIgnoreSourcePackages and packages on the destination side can be ignored with missinglinkIgnoreDestinationPackages:

missinglinkIgnoreDestinationPackages += IgnoredPackage("com.google.common")
missinglinkIgnoreSourcePackages += IgnoredPackage("com.example")

By default, all subpackages of the specified package are also ignored, but this can be disabled by the ignoreSubpackages field: IgnoredPackage("test", ignoreSubpackages = false).

By default missinglinkCheck reports the total conflict count, then a concise summary: how many dependencies are involved, a per-category breakdown of the conflicts, and a single ready-to-paste snippet that excludes the dependencies whose code triggers them:

206 conflicts found!
Missinglink summary: conflicts found in 4 dependencies.
 * 87 conflicts reference classes missing from the classpath
 * 119 conflicts reference members missing from classes already on your classpath
Exclude the dependencies that reference them:
    <proj>/missinglinkExcludedDependencies ++= List(
      moduleFilter(organization = "io.netty", name = "netty-common"),  // 84 missing classes, 0 missing members
      moduleFilter(organization = "io.opentelemetry", name = "opentelemetry-sdk-trace"),  // 3 missing classes, 0 missing members
      moduleFilter(organization = "org.slf4j", name = "jcl-over-slf4j"),  // 0 missing classes, 110 missing members
      moduleFilter(organization = "javax.activation", name = "javax.activation-api")  // 0 missing classes, 9 missing members
    )
Re-run with 'missinglinkVerbose := true' to see the full per-class breakdown (which class references each missing symbol, and from which methods).

Conflicts are either a missing class (CLASS_NOT_FOUND) or a missing member on a class that is present: a method (METHOD_SIGNATURE_NOT_FOUND) or a field (FIELD_NOT_FOUND). Each conflict is attributed to the JAR whose bytecode makes the reference, and the per-line comment splits that JAR's count into missing classes vs. members (methods and fields).

Set missinglinkVerbose := true for the full per-class, per-call-site breakdown.

You can exclude certain dependencies using moduleFilter:

missinglinkExcludedDependencies += moduleFilter(organization = "com.google.guava")
missinglinkExcludedDependencies += moduleFilter(organization = "ch.qos.logback", name = "logback-core")

sbt runs the missing-link analysis on the modules you have concurrently. Analysis of each module can take up a considerable amount of memory, so you might want to limit the degree of concurrency. To run missing-link at most on 4 projects at a time, add this setting to your project root.

concurrentRestrictions += Tags.limit(missinglinkConflictsTag, 4)

You can find more information about the problem statement, caveats and limitations, etc. in the upstream project missinglink.

This project is funded by the Scala Center.