On Tue, 21 Nov 2017, Aurelien Jarno wrote:
> On 2017-11-21 00:12, Mikulas Patocka wrote: > > > > > > 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. > > Yes, sorry about that, I really did the test with libc6-amd64:i386, but > mixed it when typing the mail. > > > 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. > > > > 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/. > > Those files are installed with the zz_ prefix to make sure they are > included last, and therefore after x86_64-linux-gnu.conf. It seems to > be missing on your system and is probably the root of your problem. This > file is installed by libc6:amd64. > > Aurelien I have /etc/ld.so.conf.d/x86_64-linux-gnu.conf, it contains # Multiarch support /lib/x86_64-linux-gnu /usr/lib/x86_64-linux-gnu But nonetheless, the linker prefers libc from /lib64. I have these files in /etc/ld.so.conf.d: i386-linux-gnu.conf:# Multiarch support i386-linux-gnu.conf:/lib/i386-linux-gnu i386-linux-gnu.conf:/usr/lib/i386-linux-gnu i386-linux-gnu.conf:/lib/i686-linux-gnu i386-linux-gnu.conf:/usr/lib/i686-linux-gnu libc.conf:# libc default configuration libc.conf:/usr/local/lib x86_64-linux-gnu.conf:# Multiarch support x86_64-linux-gnu.conf:/lib/x86_64-linux-gnu x86_64-linux-gnu.conf:/usr/lib/x86_64-linux-gnu x86_64-linux-gnux32.conf:# Multiarch support x86_64-linux-gnux32.conf:/lib/x86_64-linux-gnux32 x86_64-linux-gnux32.conf:/usr/lib/x86_64-linux-gnux32 zz_amd64-biarch-compat.conf:# Legacy biarch compatibility support zz_amd64-biarch-compat.conf:/lib64 zz_amd64-biarch-compat.conf:/usr/lib64 zz_i386-biarch-compat.conf:# Legacy biarch compatibility support zz_i386-biarch-compat.conf:/lib32 zz_i386-biarch-compat.conf:/usr/lib32 /etc/ld.so.conf contains just one line: include /etc/ld.so.conf.d/*.conf Mikulas
