[Pkg-rust-maintainers] Bug#981840: libslirp-helper crashes a few seconds after connection

[Christopher Obbard]

Package: libslirp-helper
Version: 4.3.0-2
Severity: grave
Justification: renders package unusable

Dear Maintainer,

libslirp-helper crashes a few seconds after connection without any
explanation on stdout or stderr, even with --debug flag set and
RUST_BACKTRACE enabled.

Debos and Fakemachine use libslirp-helper under the hood for networking,
to create a bridge network for the inner virtual machine to the outside
world. This can be tested by installing the fakemachine package and
running fakemachine using the uml backend, then trying to connect to the
network:

    $ fakemachine --backend uml wget http://google.com

As you can see, the libslirp-helper process which is started by
fakemachine quits.

>From investigation, I think this is because libslirp-helper was patched
to be compiled with an older version of the mio crate (0.6.16) while the
libslirp-helper Cargo.toml requires a newer version of mio (0.6.19).

These dependencies for this package were relaxed since mio version
0.6.16 was already packaged for debian.

When manually building the package with mio version 0.6.16, I get the
same error described above. So I am pretty sure that bumping mio will
sort this out.

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-1-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages libslirp-helper depends on:
ii  libc6      2.31-9
ii  libgcc-s1  10.2.1-3
ii  libslirp0  4.4.0-1

libslirp-helper recommends no packages.

libslirp-helper suggests no packages.

-- no debconf information