[slf4j-user] Seemingly basic problem with OSGi manifests

[Benson Margulies]

In all versions of SLF4J that I've looked at after 1.6.0, the
slf4j-api MANIFEST.MF looks like (this is in 1.7.21):

Import-Package: org.slf4j.impl;version=1.6.0

But the backends (e.g. slf4j-log4j12) say:

Export-Package: org.slf4j.impl;version=1.7.21

This doesn't fit together, it leads to unresolved package wiring. I
think I ran into this because, for the first time, I accidently loaded
slf4j-api into a container, instead of plugging it into the system
bundle.

I suppose that I'm missing something basic here, but what?