Bug#875775: FTBFS with Java 9: javadoc -source 9

[Chris West]

Source: mvel
Version: 2.3.1
Severity: normal
User: debian-java at lists.debian.org
Usertags: default-java9

This package fails to build with default-jdk pointing to openjdk-9-jdk.
Please fix it, so that we can start the transition to Java 9.
The wiki has some common problems and their solutions:
https://wiki.debian.org/Java/Java9Pitfalls

The javadoc build seems to be trying to use -source 9, even though the
rest of the build uses -source 1.6. As the code uses _ as an identifier,
it's necessary to run the javadoc build with a -source of 1.8 or below.

The presence of the _ is probably a problem, for which I raised upstream issue:
https://github.com/mvel/mvel/issues/132

(Also, the homepage URL in the package is wrong; it's moved to github.)


Build log:

Loading source files for package org.mvel2.templates.util.io...
Loading source files for package org.mvel2.util...
10 errors
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Skipping mvel
[INFO] This project has been banned from the build due to previous failures.
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 42.972 s
[INFO] Finished at: 2017-08-30T21:18:44Z
[INFO] Final Memory: 25M/84M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:2.10.4:jar (default-cli) on project mvel2: MavenReportException: Error while generating Javadoc: 
[ERROR] Exit code: 1 - /build/mvel-2.3.1/src/main/java/org/mvel2/util/Make.java:32: error: as of release 9, '_' is a keyword, and may not be used as an identifier
[ERROR]     public Map<K, V> _(K key, V value) {
[ERROR]                      ^
[ERROR] /build/mvel-2.3.1/src/main/java/org/mvel2/util/Make.java:37: error: as of release 9, '_' is a keyword, and may not be used as an identifier
[ERROR]     public java.util.Map<K, V> _() {
[ERROR]                                ^


Cheers,
Chris.