On Wed, Sep 15, 2021 at 12:35:38PM +0100, Simon McVittie wrote: > https://salsa.debian.org/debian/tech-ctte/-/blob/master/994388_merged_usr_advice/draft.md
Many thanks for your work, and sorry for not participating earlier. I agree with you that it would be good to send advice out sooner rather than later. I also agree with pretty much all you're saying in the text. In particular: > Questions for the committee: > > - §(Definitions and current status): Does everyone agree with my > characterization of where we are now? Ack from me. > - §(Upgrade path from Debian 11 to Debian 12): Does everyone agree > with what I've written here about the implications of #978636? I think I can follow the logic, and I agree with it. > - §(Upgrade path from Debian 11 to Debian 12): Is the last paragraph > "If a suitable transition mechanism is not available by the time the > Debian 12 freeze is reached..." necessary, or is it implicit that > *obviously* we won't demand that the project carries on with merged-/usr > if it turns out not to be possible? I think it should be included. > - §(Testing and QA): Do we want to recommend this? It does feel a bit like micro-managing to me. But the reasoning makes sense. I'm fine with recommending it. > - §(Building packages): Does everyone agree with my interpretation of > what we agreed in #914897 and its implications? Do we need to make a > recommendation for the Debian 12 development cycle, or is it enough > to assume that the "middle" option that we resolved in #914897 > continues to be our opinion? I agree and I don't think we need a new recommendation. > - §(Building packages): I almost wrote an extra paragraph about how > this class of bugs becomes a non-issue when merged-/usr is the only > supported layout - but actually it doesn't! If we consider building > packages while having /usr/local/bin/sed to be a supported thing you > can do, then we need to ensure that /usr/local/bin/sed doesn't get > hard-coded into the resulting package, and the steps you take to > make that happen are the same as the steps you take to fix this class > of bugs. FWIW I think we've traditionally considered such /usr/local -related issues as bugs in the build setup rather than in the packages. > - §(Moratorium on moving files' logical locations into /usr): > I think we should stop moving files into /usr on an individual basis, > at least until the consequences are fully understood, and perhaps for > the whole Debian 12 release cycle (after which, assuming merged-/usr > goes as we have recommended, maintainers can swap their logical location > without needing a transitional mechanism any more). Implementing > merged-/usr as the only supported layout means that moving files into > /usr on an individual basis is mostly unnecessary, because it has no > practical effect any more. Agreed on the moratorium, mainly because of the unnecessity and the error-prone nature of the moves. Sam brought up concerns about the Replaces failure mode mentioned in the text, that part might need changing. On Mon, Sep 27, 2021 at 10:59:37AM +0100, Simon McVittie wrote: > I am a little concerned that usrmerge is doing more intrusive surgery on > a running system than even what's normal for an apt/dpkg-based upgrade, > so I would prefer not to rule out designs that defer this action to a > later time. I share this concern. -- Niko