Török Edwin created MCOMPILER-233:
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Summary: Default build mode doesn't recompile all dependencies,
causing NoSuchMethodError/NoSuchFieldError at runtime
Key: MCOMPILER-233
URL: https://jira.codehaus.org/browse/MCOMPILER-233
Project: Maven Compiler Plugin
Issue Type: Bug
Affects Versions: 3.0, 2.0.2
Environment: Linux amd64
Reporter: Török Edwin
Attachments: build.log
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 http://jira.codehaus.org/browse/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
cat >src/main/java/com/example/bug/App.java <<EOF
package com.example.bug;
public class App
{
public static void main( String[] args )
{
System.out.println( new Other().foo() );
}
}
EOF
cat >src/main/java/com/example/bug/Other.java <<EOF
package com.example.bug;
public class Other {
Integer foo() { return new Integer(42); }
}
EOF
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
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