Hey,
Regarding the GCC ABI 5 issue, I was wondering what's the policy behind updating packages on stable updates for both Debian and Ubuntu.
Our time frame is a bit constrained, and we definitely will have to take some hard decisions in the next six months, so I'd like to understand everything that is at stake before I have my own opinion.
LLVM has a 6 month major cycle, releasing around February / August. Major releases are allowed to break the ABI. Major breakages need one release warning period.
Ubuntu has a 6 month release cycle, around April / October. IIUC, major releases are allowed to have new versions of packages, but updates for the next few years have to keep within the same major release.
Debian has a -1 years release cycle (heh), and has the same major / minor policy, which makes it a lot harder to update major versions. However, I believe unstable is still not closed, nor will be in August this year, so updating to LLVM 3.9 will not be a problem, but it will mean users will have to wait a bit more to get a working LLVM.
The time frame is then:
3.8.0 released March (without the fix) Ubuntu X released April 3.9.0 releases August (hopefully with a fix) Ubuntu X+1 released October
Debian freezes ?? LLVM 3.8.1 ??
If we don't back-port GCC ABI 5 into 3.8.1, Ubuntu users will not have the fix ever, unless you *can* update to 3.9.0 in August.
Ubuntu X+1 will be fine using 3.9, as will Debian after August, unless you guys freeze before that.
I believe both Debian and Ubuntu have a trunk-based LLVM package for experimental use only, and it would be bad, but not completely broken, to recommend users to use that meanwhile.
If Debian freezes *before* 3.9.0 is out, or if Ubuntu can't update to 3.9.0 on April's release, then we'll have a strong reason to back-port the change to 3.8.x. If not, even though it will be uncomfortable for users until August, the argument is not that strong and will be hard to get it through.
Any comments? Ideas? Does any of that make sense?
cheers, --renato