Bug#1076131: libllvm18: declares itself as MA: same but is not co-installable

[Sebastian Ramacher]

Package: libllvm18
Version: 1:18.1.8-2
Severity: serious
X-Debbugs-Cc: sramacher at debian.org

While libllvm18 declares itself to be MA: same, this is no longer the
case:

# apt install libllvm18:amd64 libllvm18:i386
libllvm18 is already the newest version (1:18.1.8-2).
Installing:
  libllvm18:i386

Summary:
  Upgrading: 0, Installing: 1, Removing: 0, Not Upgrading: 0
  Download size: 0 B / 29.0 MB
  Space needed: 140 MB / 1091 GB available

Continue? [Y/n] 
debconf: delaying package configuration, since apt-utils is not installed
(Reading database ... 16581 files and directories currently installed.)
Preparing to unpack .../libllvm18_1%3a18.1.8-2_i386.deb ...
Unpacking libllvm18:i386 (1:18.1.8-2) ...
dpkg: error processing archive /var/cache/apt/archives/libllvm18_1%3a18.1.8-2_i386.deb (--unpack):
 trying to overwrite shared '/usr/lib/llvm-18/lib/libLLVM-18.so.1', which is different from other instances of package libllvm18:i386
Errors were encountered while processing:
 /var/cache/apt/archives/libllvm18_1%3a18.1.8-2_i386.deb
Error: Sub-process /usr/bin/dpkg returned an error code (1)

Taking into account the usual reverse dependencies of llvm (such as
mesa), having a co-installable libllvm18 is a requirement. I am filing
this bug as serious as member of the RT. Please do not downgrade the
severity of this bug before contacting the release team.

Cheers
-- 
Sebastian Ramacher