From mobile apps to microservices, from small startups to big enterprises, Gradle helps teams build, automate and deliver better software, faster.

Gradle Community

How does problem reporting work with incremental compile?  Let's say I run `gradlew classes` after a `gradlew clean` and I get java warnings in my code.  Then I run `gradlew classes` again and I get no warnings.  How do I get Gradle to re-report the warnings on the 2nd (incremental) compile?  To me it looks as though Gradle is saying that I've fixed the warnings.  Is there a command line arg to make sure all outstanding warnings are displayed on the incremental compile?

Well, if you do not compile the files, there are not warnings. If you want to get the warnings, you need to do the actual compile.

For example by giving `--rerun` to the task in question

`--rerun` doesn't appear to output the warnings again, it seems only `clean classes` will redisplay them.  I guess there's no kind of "problems state" stored to be able to reprint warnings.  I notice this in Intellij when the build is delegated to Gradle.  If I do a `Rebuild Project` then I'll get the warnings/errors from all projects.  If I change something in 1 subproject and run `Build project` then all those previous warnings on other subprojects disappear even though they are still issues.  Feels like they shouldn't disappear and that Gradle should be keeping them as the output of the task and reprinting that output when the task says `up to date`.

That sounds strange, that `--rerun` does not help.
I just tried it.
I used a deprecated symbol in a class and did compilation and got the deprecated warning.
I changed a different class and did compilation and got no warning.
I ran the task with `--rerun` without any source changes and I got the deprecated warning again.

Check with the timestamp of the class files whether really all were written newly after using `--rerun`, otherwise you might either have did something wrong or found a bug.

Regarding preserving the warnings for compile-avoided files, I guess you need to open a feature request for that to see what the Gradle folks think about it.

Fwiw, if you care about warnings, then you should promote them to errors (at least temporarily) with `-Werror` (for JavaCompile; other languages have equivalent functionality).

Ah - `--rerun` reports the warnings and creates new class files if I use `gradlew compileJava --rerun` but not `gradlew classes --rerun`.  Is that a bug?

Thanks for the `-Werror` info - I like the "temporary" promotion idea.

&gt; Is that a bug?
No, it's how `--rerun` works: it only applies to the exact task named on the command line. Alternatively, use `--rerun-tasks` to rerun *all* tasks.

Ah - gotcha.  Thanks for the help Vampire and Thomas