Hello.  After discussion on this bug on IRC with Robie Basak, we cannot consider this SRUable in its current state.

There are multiple considerations:  (1) Trusty has 2.0.x; Vivid, Utopic have 2.1.x.  (2) The SRU process (https://wiki.ubuntu.com/StableReleaseUpdates).  (3) Vivid and Utopic are of the same 2.1.x chain, however we have no verification that between 2.1.3 and 2.1.5 there are bugfix-only fixes.

This is not SRUable for several major considerations:

(1) 2.1.5 is not just a bugfix release.  There are likely other changes other than bugfixes in 2.1.5 that can increase breakage of the version compatibility with the version in Trusty now.  If 2.1.5 were a bugfix only release, it could possibly be 'version bumped' in Trusty to fix the bugs, however this does not appear to be the case here.  As a result of this being the case...

(2) Regression potential here is extremely high.  When releasing bugfixes per SRUs, we have to be as nitpicky as we can be with fixes.  SRUs are viable in certain circumstances (https://wiki.ubuntu.com/StableReleaseUpdates#When).  SRUs, by nature, are bugfixing, and not new-feature-introduction.  As there are likely some fairly substantial changes between 2.0.x and 2.1.x, there could be a breakage of existing functionality in 2.0.x, and it could break compatibility.  Whether this is the case or not does not matter, as the version change between 2.0.x and 2.1.x could introduce a large number of regression possibilities.


With the regression potential being infinitely high in Trusty, and no details (currently) included here regarding 2.1.3 - 2.1.5 changes and whether it's a bugfix only situation, I am marking this "Incomplete" across the board.

To reiterate, this is currently not SRUable in the current state.  There has to be a lot of testing if a version bump happens, and for at least Trusty, a version bump as requested here would introduce a major risk of regressions going from 2.0.x to 2.1.5.

I strongly suggest that we could get individual bugfixes SRU'd in, but a full release of 2.1.5 to older versions is not in the nature of SRUs per the policy document.