[MCOMPILER-233] Default build mode doesn't recompile all dependencies, causing NoSuchMethodError/NoSuchFieldError at runtime

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Incomplete
• Affects Version/s: 2.0.2, 3.0
• Environment: Linux amd64
• Assignee: Robert Scholte
• Reporter: Török Edwin
• Created: 17/Sep/14 02:50
• Updated: 13/Jan/17 10:53
• Resolved: 13/Jan/17 10:53

Description

I build a project with 'mvn package', change the type of a field/method in one source file, run 'mvn package' again and it only rebuilds the changed file, and not the other classes that depend on it.
This can cause NoSuchMethodError/NoSuchFieldError when/if the code is reached at runtime. (at least Java 1.7 didn't detect this at class load time).

Due to MCOMPILER-209 it is not entirely obvious how to turn off these partial builds, for example if I put <useIncrementalCompilation>true</useIncrementalCompilation> in my pom.xml then both source files are recompiled and the program works correclty so I would think that incremental compilation is NOT used in that case? Confusing.

It appears that the only reliable way to build a project is to run 'mvn clean package' instead of just 'mvn package'.

Maven should probably print a warning when using the partial builds, and the documentation should be updated to warn of these inconsistencies.
Or perhaps you could run a final checking step after all files are compiled that checks whether the .class files are all still consistent (like a linker step).

Self-contained testcase:

#!/bin/sh
set -e

# Setup initial project
mvn archetype:generate -DgroupId=com.example.bug -DartifactId=build-bug -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false
cd build-bug

src/main/java/com/example/bug/App.java

package com.example.bug;

public class App
{
    public static void main( String[] args )
    {
        System.out.println( new Other().foo() );
    }
}

src/main/java/com/example/bug/Other.java

package com.example.bug;

public class Other {
    Integer foo() { return new Integer(42); }
}

mvn package java -cp target/build-bug-1.0-SNAPSHOT.jar com.example.bug.App

# Make a change
sed -i -e 's/Integer/Long/g' src/main/java/com/example/bug/Other.java

# Watch how incremental compilation breaks everything
mvn -X package >build.log
java -cp target/build-bug-1.0-SNAPSHOT.jar com.example.bug.App