java-commons-collections-3.2.2 does not build on wip-change-default-java8

[Boskovits]

Error:
[javac] /tmp/guix-build-java-commons-collections-3.2.2.drv-0/commons-collections-3.2.2-src/src/java/org/apache/commons/collections/MultiHashMap.java:334: error: remove(Object,Object) in MultiHashMap cannot implement remove(Object,Object) in Map
[javac] public Object remove(Object key, Object item) {
[javac] ^
[javac] return type Object is not compatible with boolean
[javac] /tmp/guix-build-java-commons-collections-3.2.2.drv-0/commons-collections-3.2.2-src/src/java/org/apache/commons/collections/MultiMap.java:69: error: remove(Object,Object) in MultiMap clashes with remove(Object,Object) in Map
[javac] public Object remove(Object key, Object item);
[javac] ^
[javac] return type Object is not compatible with boolean
[javac] /tmp/guix-build-java-commons-collections-3.2.2.drv-0/commons-collections-3.2.2-src/src/java/org/apache/commons/collections/map/MultiKeyMap.java:200: error: remove(Object,Object) in MultiKeyMap cannot implement remove(Object,Object) in Map
[javac] public Object remove(Object key1, Object key2) {
[javac] ^
[javac] return type Object is not compatible with boolean
[javac] /tmp/guix-build-java-commons-collections-3.2.2.drv-0/commons-collections-3.2.2-src/src/java/org/apache/commons/collections/map/MultiValueMap.java:156: error: remove(Object,Object) in MultiValueMap cannot implement remove(Object,Object) in Map
[javac] public Object remove(Object key, Object value) {
[javac] ^
[javac] return type Object is not compatible with boolean
[javac] Note: Some input files use unchecked or unsafe operations.
[javac] Note: Recompile with -Xlint:unchecked for details.
[javac] 4 errors

BUILD FAILED
/tmp/guix-build-java-commons-collections-3.2.2.drv-0/commons-collections-3.2.2-src/build.xml:129: Compile failed; see the compiler error output for details.

Total time: 2 seconds
phase build' failed after 2.6 seconds note: keeping build directory /tmp/guix-build-java-commons-collections-3.2.2.drv-0'
builder for /gnu/store/y1mb5g7y30fh8iskvkymlarhnm3b4ms6-java-commons-collections-3.2.2.drv' failed with exit code 1 @ build-failed /gnu/store/y1mb5g7y30fh8iskvkymlarhnm3b4ms6-java-commons-collections-3.2.2.drv - 1 builder for /gnu/store/y1mb5g7y30fh8iskvkymlarhnm3b4ms6-java-commons-collections-3.2.2.drv' failed with exit code 1

[Boskovits]

Known upstream, cannot change public api, fixed in 4.0.

1. Do we really need this?
   I plan to make the target and source 1.7.

Yes, unfortunately we need this, beanutils depends on it, no newer version available.

It seems, that changing the target and source is not enough.
The compilation fails the same way, complaining about no bootstrap classpath for 1.7

[Boskovits]

There are several patches addressing the issue, but it can't be done on a backwards compatible way.
Should we use that?
Altrenatively it could be possible to set this for java7 default, and wait for the beanutils 2 release, when we can remove this.

[Boskovits]

Temporary fix on commit bf1bd7d.