Gradle: Neither path nor baseDir may be null or empty string

Question

I am trying to use ProGuard in my Gradle script to obfuscate my code everytime I build, however I am running into the following error:

FAILURE: Build failed with an exception.

* What went wrong:
Neither path nor baseDir may be null or empty string. path='null' basedir='/Users/hassansyyid/Workspace/Random/Launcher/launcher'

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 1.888 secs

Here is my build.gradle:

import proguard.gradle.ProGuardTask

apply plugin: 'com.github.johnrengelman.shadow'

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'net.sf.proguard:proguard-gradle:5.3.1'
    }
}

jar {
    manifest {
        attributes("Main-Class": "com.skcraft.launcher.Launcher")
    }
}

dependencies {
    compile 'org.projectlombok:lombok:1.12.2'
    compile 'com.fasterxml.jackson.core:jackson-databind:2.3.0'
    compile 'commons-lang:commons-lang:2.6'
    compile 'commons-io:commons-io:1.2'
    compile 'com.google.guava:guava:15.0'
    compile 'com.beust:jcommander:1.32'
    compile 'com.miglayout:miglayout:3.7.4'
    compile 'com.google.code.findbugs:jsr305:3.0.0'
}

processResources {
    filesMatching('**/*.properties') {
        filter {
            it.replace('${project.version}', project.version)
        }
    }
}

task obfuscate(type: proguard.gradle.ProGuardTask) {
  configuration 'proguard.txt'

  injars "${buildDir}/libs/launcher-${version}.jar"
  outjars "${buildDir}/libs/launcher-${version}-obf.jar"

  libraryjars configurations.compile.find { it.name.startsWith("lombok") }
  libraryjars configurations.compile.find { it.name.startsWith("jackson-databind") }
  libraryjars configurations.compile.find { it.name.startsWith("jackson-core") }
  libraryjars configurations.compile.find { it.name.startsWith("jackson-annotation") }
  libraryjars configurations.compile.find { it.name.startsWith("crypto") }
  libraryjars configurations.compile.find { it.name.startsWith("guava") }
  libraryjars configurations.compile.find { it.name.startsWith("jcommander") }
  libraryjars configurations.compile.find { it.name.startsWith("miglayout") }
  libraryjars configurations.compile.find { it.name.startsWith("jsr305") }
  libraryjars configurations.compile.find { it.name.startsWith("commons-io") }
  libraryjars configurations.compile.find { it.name.startsWith("commons-lang") }
}

shadowJar {
    dependencies {
        exclude(dependency('org.projectlombok:lombok'))
    }
}

build.dependsOn(shadowJar)
build.dependsOn(obfuscate)

The only information I figured out about the issue is that it is related to the obfuscate task. I confirmed this by commenting out build.dependsOn(obfuscate) and the build was successful.

I looked up the error but was unable to find any useful information. Also, I am running Gradle 3.1, the latest Gradle build.

My proguard.txt:

# Include java runtime classes
-libraryjars  <java.home>/lib/rt.jar

# Output a source map file
-printmapping proguard.map

# Keep filenames and line numbers
-keepattributes SourceFile, LineNumberTable

# Disable certain proguard optimizations which remove stackframes (same as Android defaults)
-optimizations !method/inlining/*

-keep public class * {
    public protected *;
}

-keepclassmembernames class * {
    java.lang.Class class$(java.lang.String);
    java.lang.Class class$(java.lang.String, boolean);
}

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();
}

Thanks in advance for any help!

Answer 1

The problem seems to be the way you declare the library jars in the ProGuard task. According to the documentation at the ProGuard homepage one needs to specify a file collection for the libraryjars setting.

Class paths are specified as Gradle file collections, which means they can be specified as simple strings, with files(Object), etc.

I updated your gradle file and was able to successfully run the build:

import proguard.gradle.ProGuardTask

apply plugin: 'com.github.johnrengelman.shadow'
apply plugin: 'java'

buildscript {
  repositories {
    mavenCentral()
    jcenter()
  }

  dependencies {
    classpath group: 'net.sf.proguard', name: 'proguard-gradle', version: '5.3.1'
    classpath group: 'com.github.jengelman.gradle.plugins', name: 'shadow', version: '1.2.4'
  }
}

repositories {
  mavenCentral()
  jcenter()
}

jar {
  manifest { attributes("Main-Class": "com.skcraft.launcher.Launcher") }
}

dependencies {
  compile 'org.projectlombok:lombok:1.12.2'
  compile 'com.fasterxml.jackson.core:jackson-databind:2.3.0'
  compile 'commons-lang:commons-lang:2.6'
  compile 'commons-io:commons-io:1.2'
  compile 'com.google.guava:guava:15.0'
  compile 'com.beust:jcommander:1.32'
  compile 'com.miglayout:miglayout:3.7.4'
  compile 'com.google.code.findbugs:jsr305:3.0.0'
}

processResources {
  filesMatching('**/*.properties') {
    filter {
      it.replace('${project.version}', project.version)
    }
  }
}

task obfuscate(type: proguard.gradle.ProGuardTask) {
  configuration 'proguard.txt'

  injars jar
  outjars "${buildDir}/libs/launcher-${version}-obf.jar"

  libraryjars files(configurations.compile.collect())
}

shadowJar {
  dependencies {
    exclude(dependency('org.projectlombok:lombok'))
  }
}

build.dependsOn(shadowJar)
build.dependsOn(obfuscate)


task wrapper(type: Wrapper) { gradleVersion = "3.1" }