Bug#912998: llvm-toolchain-snapshot: Conflicts not advertised

[Marc Glisse]

Source: llvm-toolchain-snapshot
Version: 1:8~svn343154-1
Severity: normal

Dear Maintainer,

I recently tried to upgrade from older libc++-dev (& others). Those were
multiarch-capable, so I had installed them for several architectures.
This appears to have been broken in the new organisation. For instance
/usr/lib/llvm-8/lib/libc++.so.1.0 is not in an arch-specific directory.
However, the packages are still advertised as "Multi-Arch: same", so I
only noticed during the installation. It would be nice to make the
packages multi-arch-friendly again, better than just fixing the
Multi-Arch field, although that would be better than nothing.

To make progress, on this machine, I removed all foreign versions of
those packages and was able to install the llvm-7 version of everything
for x86_64. Since I also noticed llvm-8 packages, I decided to try and
install them, and again, apt was happy to oblige, until during the
installation it noticed some conflicts, like
/usr/lib/x86_64-linux-gnu/libc++.a. It kind of looks like libc++1-7 and
libc++1-8 are meant to conflict, but if they are not, you might need to
use alternatives or diversions.

-- System Information:
Debian Release: buster/sid
   APT prefers unstable-debug
   APT policy: (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'testing'), (500, 'stable'), (50, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.18.0-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled