Question: My software builds use `-Xlint -Werror` so I routinely run across compiler warnings that break my build. Every once in a while I run across a warning that I need to suppress, but it's always difficult to figure out which `Xlint` option suppresses the warning I am seeing.

I'll give you a concrete example. I recently ran across:

```
[WARNING] module-info.java:[16,106] module not found: 
    org.bitbucket.cowwoc.requirements.guava

```

I searched the JDK 11 source-code and discovered this warning message declared at `/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties` as:

```
# 0: symbol
compiler.err.module.not.found=\
    module not found: {0}

```

Now, it turns out that this is suppressed by `-Xlint:-module` but that's not obvious from the documentation. `-Xlint:-export` could made sense as well. I've also run across warnings in the past that couldn't be suppressed at all (these were subsequently fixed).

Instead of resorting to trial and error, **is there a deterministic way to figure out which `Xlint` option corresponds to each warning message**? Is there some sort of mapping file somewhere in the JDK source codes?

**UPDATE**: I am using Maven 3.6.0, maven-compiler-plugin 3.8.0, JDK 11.0.1

Answer: 
One way to do that, if somehow you're not able to access the [online documentation](https://docs.oracle.com/en/java/javase/11/tools/javac.html#GUID-AEEC9F07-CB49-4E96-8BC7-BCC2C7F725C9) could be using the command 

```
javac --help-extra

```

This would list out the possible warnings that you could enable/disable. For example from ***`javac 12-ea`*** :

[![enter image description here](https://i.stack.imgur.com/W44GG.png)](https://i.stack.imgur.com/W44GG.png)
Alan Bateman pointed me in the right direction. It seems that the maven-compiler-plugin suppressing vital information. Here is the output from javac 11.0.1:

```
C:\Users\Gili\Documents\requirements\java\src\main\java\module-info.java:16: warning: [module] module not found: org.bitbucket.cowwoc.requirements.guava
        exports org.bitbucket.cowwoc.requirements.java.internal.impl to org.bitbucket.cowwoc.requirements.guava;

```

Here is the corresponding output from maven-compiler-plugin:

```
[WARNING] /C:/Users/Gili/Documents/requirements/java/src/main/java/module-info.java:[16,106] module not found: org.bitbucket.cowwoc.requirements.guava

```

`javac` mentions `[module]` at the beginning of the warning, indicating that `-Xlint:-module` will suppress this warning.

I filed a bug report here: <https://issues.apache.org/jira/browse/MCOMPILER-367>