Thanks for the mentioning the trick. I experimented a bit and it seems,
"invoker.toolchain.jdk.version" is indeed working as expected. It was
probably a temporary hickup on the jenkins build nodes.
However, toolchains.xml is only available on linux nodes, not on Windows
nodes. I've create a INFRA ticket for that .
In order to have my new integration test working for both linux and
windows, I'm using now a custom selector script . This script copies
the user's (jenkin's) toolchains.xml file into the integration test, if
available. Under Windows, it creates a new toolchains.xml using a fixed
path to the jdk (F:\jenkins\tools\java\latest11).
While looking at other plugins, I found two integration tests in
m-compiler-p which were not being executed due to referencing a
non-existing toolchain. I've fixed and enabled these tests (for linux only).