Recently when doing and emerge -uD world, the package dev-lang/R will want to be upgraded to 2.2.1-r1 and then after a later emerge --sync it will want to be downgraded again. This has happened several times, so I imagine there's a circular dependency of some sort.
Steps to Reproduce:
2.emerge -uD world
It wishes to either upgrade to R-2.2.1-r1 or downgrade to R-2.2.1 depending on which is presently installed
Not constantly cycle between the two versions of R
Post the actual emerge output both on upgrade and downgrade. Cannot help without any information available, sorry.
What happens is that if I type in emerge -uDp world it says:
[ebuild U ] dev-lang/R-2.2.1-r1 [2.2.1]
Later, after emerging this, and, I think, emerge --synch'ing, I get this when I emerge -uDp world.
[ebuild U ] dev-lang/R-2.2.1 [2.2.1-r1]
Is this what you were looking for?
No, not really. We need to know which package is causing this and you didn't post any context whatsoever.