What is the policy on backporting paper cuts fixes?

Question

I've just reported a paper cut in the current LTS release and was wondering if I will ever see the fix backported, or if I'm going to have to upgrade so get it.

Answer 1

In almost all circumstances, a paper cut fix will not be backported. Only paper cuts with a high importance will be submitted, and even then it's not guaranteed to be approved.

All Stable Release Updates are approved with caution. Full details about what they are and how they work can be found here, but the passage of importance is this:

Stable release updates are automatically recommended to a very large number of users, and so it is critically important to treat them with great caution. Therefore, when updates are proposed, they must be accompanied by a strong rationale and present a low risk of regressions.

"It's just a one-line change!" Even the simplest of changes can cause unexpected regressions due to lurking problems:

• In bug 81125, the upgrade regression had nothing to do with the content of the change that triggered it: any user who had installed the libpthread20 package would encounter a problem the next time libc6 was upgraded.
• In bug 309674, the failure was a misbuild due to timestamp skew in the build process. The underlying problem existed in the source package in the original release, but would only manifest in a small percentage of builds.
• In bug 559822, a C++ library (wxwidgets2.8) was uploaded with no code changes. Due to an underlying toolchain change/bug, this caused an ABI change, causing a lot of unrelated packages to break (see bug 610975).

We never assume that any change, no matter how obvious, is completely free of regression risk.

The definition of a paper cut requires the problem to be minor, meaning the need to backport it will be low to non-existent. Only paper cuts with a high importance will be considered for SRU, and these will be few and far between.