Can someone tell me what I am doing wrong to align dependency versions across projects?

I am stuck. Trying to learn how to do this (as can be seen in Need more details on using platforms to align dependency versions in a multi-project setup) but am failing.

I created a minimal project set to experiment with and didn’t get very far. I get “FAILED” dependency resolutions and unexpected (to me, not aligned) resolved dependency versions. Attached is the small 3 kilobyte archive of that project:

platform-experiment.zip (2.8 KB)

What my goal is that, while exact (sub)set of all dependencies may differ between the three main projects in my experiment (‘a’, ‘b’ and ‘c’), any one dependency module will always have consistent/aligned version for each - the same across all three projects.

I thought that setting up a “platform” project (‘library’ in my case) will allow me to somehow force all dependency resolution to be brought together to it, forced resolved in there, coordinated.

What am I doing wrong?

Thanks!

P.S. I am intentionally not using the Java platform plugin - we’re neither all Java nor we match its assumptions.