Unable to use AllErrorsAsWarnings flag in Maven

[cojoco]

Description of the problem / feature request:

I am unable to downgrade all errors to warnings using the '-XepAllErrorsAsWarnings' flag (as seen here)

When I run mvn compile without the flag, I (correctly) get the following error:

[ERROR] /Users/ccook/projects/test-app/src/main/java/com/testgroup/testapp/App.java:[15,8] error: [DeadException] Exception created but not thrown
    (see https://errorprone.info/bugpattern/DeadException)
  Did you mean to remove this line?

When I run with the flag, I get the following error:

[ERROR] javac: invalid flag: -XepAllErrorsAsWarnings
Usage: javac <options> <source files>
use --help for a list of possible options

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

Run mvn compile in the same directory as the pom.xml in the unzipped test-app
test-app.zip

What version of Error Prone are you using?

2.3.2

I am also using Maven version 3.5.4 and Java version 1.8.0_181 on OS X (updated to Mojave).

Have you found anything relevant by searching the web?

Unfortunately not. I'm guessing I'm just doing something wrong, since nobody else seems to be having this issue.

[Stephan202]

You're hit by a Java 8-specific issue, described in #1115.

Possible fix:

diff --git a/pom.xml b/pom.xml
index 9e25de2..2a9030b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -35,8 +35,7 @@
           <target>8</target>
           <compilerArgs>
             <arg>-XDcompilePolicy=simple</arg>
-            <arg>-Xplugin:ErrorProne
-                 -XepAllErrorsAsWarnings</arg>
+            <arg>-Xplugin:ErrorProne -XepAllErrorsAsWarnings</arg>
           </compilerArgs>
           <annotationProcessorPaths>
             <path>

Or if you plan to add many more flags:

diff --git a/pom.xml b/pom.xml
index 9e25de2..77a6785 100644
--- a/pom.xml
+++ b/pom.xml
@@ -35,8 +35,8 @@
           <target>8</target>
           <compilerArgs>
             <arg>-XDcompilePolicy=simple</arg>
-            <arg>-Xplugin:ErrorProne
-                 -XepAllErrorsAsWarnings</arg>
+            <arg>-Xplugin:ErrorProne<!--
+            -->  -XepAllErrorsAsWarnings</arg>
           </compilerArgs>
           <annotationProcessorPaths>
             <path>

[cojoco]

I tried the first fix. It did get rid of the error, but the compilation did not show the DeadException as a warning. Do I need to add another flag to get the warning to show?

[cojoco]

I needed to add <showWarnings>true</showWarnings> to the maven-compiler-plugin configuration to get the warnings to show.

diff --git a/pom.xml b/pom.xml
index b5727d4..71c1aca 100644
--- a/pom.xml
+++ b/pom.xml
@@ -33,9 +33,10 @@
         <configuration>
           <source>8</source>
           <target>8</target>
+          <showWarnings>true</showWarnings>
           <compilerArgs>
             <arg>-XDcompilePolicy=simple</arg>
-            <arg>-Xplugin:ErrorProne</arg>
+            <arg>-Xplugin:ErrorProne -XepAllErrorsAsWarnings</arg>
           </compilerArgs>
           <annotationProcessorPaths>
             <path>

I think that's all I needed, thanks!