On Sat, Aug 05, 2017 at 11:50:42PM +0200, Guus Sliepen wrote: > On Sat, Aug 05, 2017 at 07:53:02PM +0200, Adam Borowski wrote: > > > Thus, here's a proposed solution: in unstable, there's now a bunch of > > packages that do such checking in preinst, and thus refuse (overridably) to > > even install such software. > [...] > > A big issue here is that install-time is different than run-time. I see > at least two possible scenarios where this construction fails: > > - Motherboard dies, move harddisks to old computer with older CPU, > suddenly things start failing at run-time again. > > - Preparing a Debian image on a fast new machine, use the image on an > older/embedded device.
Hmm right, this one indeed might be an issue. We wouldn't be worse off than the current state, though. Do you perhaps have any ideas? > Also conversely, trying to install something on an old machine, or in a > limitted VM environment, with the intention of later using it on a newer > machine, will now fail. A limited VM is ok, as no check looks at /proc or something that may be missing, just tests on the CPU itself. As for a foreign machine: * ISA_IGNORE=y apt install »package« * if installing for a wholly different architecture (and without qemu), the check is skipped -- no way to probe the target machine anyway > Maybe a debconf question can be asked when installing one of these > proposed packages to allow installation anyway even if the current host > machine does not support the requested instruction set. I thought about it but decided against, as it seemed to me it's a situation too unlikely to happen (usually it's the big computer installing something for a SoC or a museal piece) -- at least not likely enough to warrant confusing new users. If you guys disagree, though, it's not a big change. There's a reason why I raised this thread instead of rushing on a mass bug filing... Meow! -- ⢀⣴⠾⠻⢶⣦⠀ What Would Jesus Do, MUD/MMORPG edition: ⣾⠁⢰⠒⠀⣿⡁ • multiplay with an admin char to benefit your mortal ⢿⡄⠘⠷⠚⠋⠀ • abuse item cloning bugs (the five fishes + two breads affair) ⠈⠳⣄⠀⠀⠀⠀ • use glitches to walk on water