GitHub user zentol opened a pull request:
https://github.com/apache/flink/pull/5644
[FLINK-8847][build] Prevent unnecessary recompilation
## What is the purpose of the change
This PR contains 2 changes to prevent the `maven-compiler-plugin` from
recompiling a module that doesn't require it.
The `maven-compiler-plugin` will now always create `.class` files for
`package-info.java` files. Previously this was only done if the `.java` file
contained annotations.
Having a `.java` file without a corresponding `.class` file throws of the
`maven-compiler-plugin` stale source detection, as described in
[MCOMPILER-205](https://issues.apache.org/jira/browse/MCOMPILER-205).
Additionally, `useIncrementalCompilation` is set to false which actually
enables incremental compilation, as described in
[MCOMPILER-209](https://issues.apache.org/jira/browse/MCOMPILER-209).
## Brief change log
* create `.class` files for all `package-info.java` files
* set `useIncrementalCompilation` to false which actually enables
incremental compilation
## Verifying this change
Pick any module that contains a `package-info.java` file (like
`flink-optimizer`) and run `mvn package <speed options>` twice. The plugin
should not recompile the module.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/zentol/flink 8847
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/5644.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #5644
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commit 293795b5e5f57dba07e985be9e46ba2534e91eac
Author: zentol <chesnay@...>
Date: 2018-03-06T09:45:25Z
[FLINK-8847][build] Always generate .class files for package-info.java
commit 92d17feab6cd604fd2bd2be96d6ed35485c13b80
Author: zentol <chesnay@...>
Date: 2018-03-06T10:04:42Z
[hotfix][build] Enable incremental compilation
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