[MCOMPILER-534] Document conditional setting of the --release property

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.11.0
• Fix Version/s: 3.12.0

Environment

Apache Maven 3.9.1 (2e178502fcdbffc201671fb2537d0cb4b4cc58f8)
Maven home: /usr/local/Cellar/maven/3.9.1/libexec
Java version: 1.8.0_362, vendor: Homebrew, runtime: /usr/local/Cellar/openjdk@8/1.8.0+362/libexec/openjdk.jdk/Contents/Home/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "13.3.1", arch: "x86_64", family: "mac"

Darwin **** 22.4.0 Darwin Kernel Version 22.4.0: Mon Mar 6 21:00:17 PST 2023; root:xnu-8796.101.5~3/RELEASE_X86_64 x86_64

• Assignee: Michael Osipov
• Reporter: Gary D. Gregory
• Created: 23/Apr/23 13:32
• Updated: 22/Oct/23 14:48
• Resolved: 01/May/23 11:10

Description

Apache Commons Parent 57 RC1 (https://lists.apache.org/thread/rwgf9c7dgl2bymq3jg6ckxs6gk9pz4mg) attempts to use the javac release flag only on Java 9 and above with 

<maven.compiler.release>8</maven.compiler.release>

and

    <profile>
      <id>jdk9-compiler</id>
      <activation>
        <jdk>[9</jdk>
      </activation>
      <build>
    	<pluginManagement>
   	      <plugins>
            <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-compiler-plugin</artifactId>
              <configuration>
                <release>${maven.compiler.release}</release>
              </configuration>
            </plugin>
          </plugins>
        </pluginManagement>
      </build>
    </profile>

This fails miserably:

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  5.402 s
[INFO] Finished at: 2023-04-23T09:23:21-04:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project commons-lang3: Fatal error compiling: invalid flag: --release -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

IMO, setting a property "maven.compiler.release" should not be used on compilers that do not support the flag.

Issue Links

• links to: GitHub Pull Request #187