On Mon, 20 Nov 2017, Aurelien Jarno wrote:
> On 2017-11-20 19:13, Mikulas Patocka wrote: > > Package: libc6-amd64 > > Version: 2.25-1 > > Severity: critical > > Justification: breaks the whole system > > > > Dear Maintainer, > > > > *** Reporter, please consider answering these questions, where appropriate > > *** > > > > * What led up to the situation? > > > > I have a x86-64 system with i386 and x32 foreign architectures (because I > > need to develop software for i386 and x32 architectures). > > > > * What exactly did you do (or not do) that was effective (or > > ineffective)? > > > > I ran apt update and apt upgrade. Apt tried to upgrade to libc-2.25. > > > > * What was the outcome of this action? > > > > Halfway through apt upgrade it failed and I ended up with unusable system > > where > > large number of binaries were segfauting on startup without doign anything. > > > > * What outcome did you expect instead? > > > > The upgrade to libc-2.25 should work. > > > > > > The reason for the catastrophic failure is this: > > > > There is package libc6-amd64:i386 and libc6-amd64:x32 (which provide > > I guess you mean you have installed one of the two, not both. > > > x86-64 libc in /lib64/). This package is not technically needed (because > > x86-64 libc is already installed in /lib/x86_64-linux-gnu/), but it is > > installed nonetheless because of some dependencies. > > Just to be clear, as said in my other email, this *is* technically > needed as gcc-multilib is not able to make use of the libc in > /lib/x86_64-linux-gnu. > > > apt makes sure that all libc packages are upgraded at once to the same > > version. However, during the upgrade process, the package > > libc6-amd64 is upgraded before libc6:amd64. So, during the upgrade, we > > temporarily have two libcs with different versions on the system, and this > > mismatch makes most of the x86-64 binaries crash. Due to the crashes, the > > upgrade doesn't proceed and it doesn't install the correct libc version in > > /lib/x86_64-linux-gnu/. > > > > The result is unusable system. > > I have done some tests, and while I confirm that libc6-i386:amd64 is The problem is with libc6-amd64:i386 or libc6-amd64:x32. Not libc6-i386:amd64. I.e. use amd64 Debian Sid base installation, add foreign architectures i386 and x32 and use this /etc/apt/sources.list: deb [ arch=i386,amd64 ] http://ftp.cz.debian.org/debian/ sid main contrib non-free deb [ arch=x32 ] http://ftp.de.debian.org/debian-ports/ unreleased main deb [ arch=x32 ] http://ftp.de.debian.org/debian-ports/ unstable main > unpacked much before libc6:amd64, it doesn't cause any issue here. > Indeed the search path in ld.so is to give higher priority to > /lib/x86_64-linux-gnu/ over /lib64. I have even been able to install > libc6:amd64 in version 2.24 (using force-all), while keeping > libc6-amd64:i386 in version 2.25. > > The only way to change the priority of the two path is using a > non-standard ld.so.conf. Have you made any change to /etc/ld.so.conf or > /etc/ld.so.conf.d/*? Maybe you can share the content of this file and > this directory. > > -- > Aurelien Jarno GPG: 4096R/1DDD8C9B > aurel...@aurel32.net http://www.aurel32.net On my system, there's a file /etc/ld.so.conf.d/zz_amd64-biarch-compat.conf containing: # Legacy biarch compatibility support /lib64 /usr/lib64 and /etc/ld.so.conf.d/zz_i386-biarch-compat.conf containing: # Legacy biarch compatibility support /lib32 /usr/lib32 These files are created by the packages libc6-i386:x32 and libc6-amd64:x32. They cause that /lib64 is preferred to /lib/x86_64-linux-gnu/. If I delete these files and run ldconfig, the linker will prefer /lib/x86_64-linux-gnu/. Mikulas
