Not a bug.
build-timeout is provided as an implementation of BuildWrapper which is applicable to `AbstractBuild`.
As pipelines don't use `BuildWrapper`, build-timeout doesn't work for pipelines.
In other words, build-timeout doesn't target pipeline for now.
> Also it would be extremely useful to update the plugin homepage (wiki) in order to document its relationship with the timeout() from pipelines.
You can do that by yourself as it is a wiki.
I don't know so much about timeout() in pipeline to write documents.