How to make Gradle fail the build if a file dependency is not found?

Question

I have a Gradle build that has some dependencies of the form

compile files('path/to/local/lib.jar')

(the build is being migrated - eventually these will be replaced)

The build failed because one of these paths was incorrectly specified. But it failed due to a compile error - it looked like Gradle silently ignored the missing dependency.

Is there a simple option or switch that will force Gradle to fail the build if any dependency (particularly local file dependencies) cannot be resolved (eg., file missing)?

Edit: to clarify further:

If a dependency cannot be found in the configured repositories, Gradle will fail the build when attempting to resolve them, as expected.

BUT - if a dependency is defined as "compile files ....", and the file specified does not exist at build time, Gradle will IGNORE that error, and attempt compilation anyway. That seems spectacularly wrong-headed and inconsistent default behaviour.

My question is - is there a Gradle option or switch or environment variable or system property that I can set to force Gradle to verify that file dependencies exist? (E.g,, behave in a sane and rational way?)

Answer 1

This is a bit of an old thread, but given that none of the currently proposed solutions actually works, and the solution appears to be trivial (collating two of them), I am leaving it here for future reference.

The point here is that we simply want to ensure that the files do exist, so we can just use the exists() method of the File class:

task ensureDepsExist() {
    doLast {
        configurations.implementation.canBeResolved(true)
        Set<File> impFiles = configurations.implementation.resolve()

        impFiles.forEach { f ->
            if (!f.exists()) {
                ant.fail "${f} could not be found"
            }
        }
    }
}

compileJava.dependsOn ensureDepsExist

The canBeResolved() call is required, or Gradle will complain that configurations dependencies cannot be resolved.

Answer 2

Here's how you can check transitive dependencies using Gradle 7.3 (example: Fail if the project depends on log4j directly or transitively).

Kotlin DSL

configurations {
  all {
    relsolutionStrategy {
      eachDependency {
        if (requested.name == "log4j") {
          throw RuntimeException("Project depends on log4j")
        }
      }
    }
  }
}

Groovy DSL

configurations.all {
    resolutionStrategy.eachDependency { DependencyResolveDetails details ->
        if (details.requested.name == 'log4j') {
            throw new RuntimeException("Project depends on log4j")
        }
    }
}