arm64v8 focal: lintian will get stuck with it

Hello, thank you for the bug report. I have been unable to recreate so far. I've been using AWS' m6g instance family as an ARM64 host. I've attempted to recreate by launching Ubuntu 16.04, 18.04, and 20.04 for host VM image and then installed docker.io from the Ubuntu archive before running the reproducer steps in the description. Each of those attempts succeeded without stalling.

Could you tell me more about the environment so we can recreate this? Thank you.

Thank you for trying to confirm this issue.

I didn't assumed that it depends on host.
I'm using Debian/unstable. The version of docker.io is:

% dpkg -l | \grep docker.io
ii docker.io 19.03.7+dfsg1-3 amd64 Linux container runtime

And only I changed for docker.io settings is `vsyscall=emulated`, explained at https://hub.docker.com/_/centos

I've recreated on an amd64 Ubuntu Server 20.04 image on AWS. I've updated the description with a newer set of reproducer instructions that uses lintian itself and details the host setup as well.

I added a -d flag to the invocation of perl in the shebang line of /usr/share/lintian/frontend/dplint Here is what I got:

# lintian --help

Loading DB routines from perl5db.pl version 1.55
Editor support available.

Enter h or 'h h' for help, or 'man perldebug' for more help.

main::(/usr/bin/lintian:55): };
  DB<1> c
^CIO::Async::Loop::Epoll::loop_once(/usr/share/perl5/IO/Async/Loop/Epoll.pm:181):
181: return undef if !defined $ret and $! != EINTR;
  DB<1> T
@ = DB::DB called from file '/usr/share/perl5/IO/Async/Loop/Epoll.pm' line 181
. = IO::Async::Loop::Epoll::loop_once(ref(IO::Async::Loop::Epoll)) called from file '/usr/share/perl5/IO/Async/Loop.pm' line 642
. = IO::Async::Loop::await(ref(IO::Async::Loop::Epoll), ref(IO::Async::Future)) called from file '/usr/share/perl5/Lintian/Util.pm' line 691
$ = Lintian::Util::safe_qx('nproc') called from file '/usr/share/perl5/Lintian/Internal/FrontendUtil.pm' line 123
@ = Lintian::Internal::FrontendUtil::default_parallel() called from file '/usr/share/lintian/commands/lintian.pm' line 82
$ = require '/usr/share/lintian/commands/lintian.pm' called from file '/usr/bin/lintian' line 36
. = eval {...} called from file '/usr/bin/lintian' line 36
. = main::__ANON__[/usr/bin/lintian:55]('/usr/share/lintian/commands/lintian.pm') called from file '/usr/bin/lintian' line 120
. = dplint::run_tool('/usr/bin/lintian', 'lintian') called from file '/usr/bin/lintian' line 299
. = dplint::main() called from file '/usr/bin/lintian' line 383

I also ran with tracing and that's attached here as

Eoan arm64 container on focal amd64 host does not recreate this issue.

I'm moving this from cloud-images to lintian, this is not an issue specific to the image itself.

Status changed to 'Confirmed' because the bug affects multiple users.

As I can see, this bug may be related to this one: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=964770
And it was closed, because of fix released in lintian 2.92.0.