Strange problem with parallel build and Java 17

[lwrage]

I just switched my development environment to Eclipse 2022-03, updated from Java 11 to 17, and switched from tycho 2.5.0 to 2.7.0. The build works fine if I run it single threaded. However, when I run a parallel build (which used to work before) I get compiler error like the one below. Interestingly, these are plugin projects with BREE JavaSE-17. Other projects with BREE JavaSE-11 or 8 compile just fine in the parallel build.

I am at a loss where to even start investigating. Does anybody have an idea what could be the cause for the error?

[ERROR] Failed to execute goal org.eclipse.tycho:tycho-compiler-plugin:2.7.0:compile (default-compile) on project org.osate.ge.gef: Compilation failure: Compilation failure: 
[ERROR] /home/lw/local/eclipse/java-2022-03/git/osate2/ge/org.osate.ge.gef/src/org/osate/ge/gef/LabelBackgroundColorUtil.java: 
[ERROR] 	/**
[ERROR] 	^
[ERROR] The type java.util.function.Function cannot be resolved. It is indirectly referenced from required .class files
[ERROR] 1 problem (1 error)
[ERROR] -> [Help 1]
[ERROR] Failed to execute goal org.eclipse.tycho:tycho-compiler-plugin:2.7.0:compile (default-compile) on project org.osate.ge.swt: Compilation failure: Compilation failure: 
[ERROR] /home/lw/local/eclipse/java-2022-03/git/osate2/ge/org.osate.ge.swt/src/org/osate/ge/swt/selectors/NullRemovingSelectorModel.java: 
[ERROR] 	/**
[ERROR] 	^
[ERROR] The type java.lang.Boolean cannot be resolved. It is indirectly referenced from required .class files
[ERROR] /home/lw/local/eclipse/java-2022-03/git/osate2/ge/org.osate.ge.swt/src/org/osate/ge/swt/selectors/NullRemovingSelectorModel.java:[33] 
[ERROR] 	class NullRemovingSelectorModel extends SelectorModelDecorator<Object> {
[ERROR] 	                                                               ^^^^^^
[ERROR] Object cannot be resolved to a type
[ERROR] 2 problems (2 errors)
[ERROR] -> [Help 1]
[ERROR] 

[lwrage]

This has been resolved. The tycho-compiler-plugin was configured wrong for the project.

[laeubi]

Do you like to explain what was the misconfiguration so we can mark this as an answer?

[lwrage]

The configuration contained <source>11</source> and <target>11</target>.