Bug#1022858: perl-base: lots of duplicate files between perl-modules-5.32 and perl-base

[Marc Lehmann]

Package: perl-base
Version: 5.32.1-4+deb11u2
Severity: minor
X-Debbugs-Cc: reportbug at plan9.de

Dear Maintainer,

I recently installed a fresh bullseye and ran jdupes to deduplicate files.

To my surprise, this reduced the installed size (on a zstd-compressed btrfs filesystem)
from 2GB to 1.3GB.

This was rather unexpected and I investigated.

One of the larger reasons for this size reduction is a large number of relatively large files
that are identical in perl-modules-5.32 and perl-base, random example:

-rw-r--r-- 1 root root 1466 Sep 24  2021 /usr/lib/x86_64-linux-gnu/perl-base/unicore/lib/Lb/CL.pl
-rw-r--r-- 1 root root 1466 Sep 24  2021 /usr/share/perl/5.32.1/unicore/lib/Lb/CL.pl

I wonder if thid duplication is intended, and if yes, maybe hardlinks should be used to save space.

-- System Information:
Debian Release: 11.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-19-amd64 (SMP w/4 CPU threads)
Locale: LANG=en_IE.UTF-8, LC_CTYPE=en_IE.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages perl-base depends on:
ii  dpkg       1.20.12
ii  libc6      2.31-13+deb11u5
ii  libcrypt1  1:4.4.18-4

perl-base recommends no packages.

Versions of packages perl-base suggests:
ii  perl            5.32.1-4+deb11u2
ii  sensible-utils  0.0.14

-- no debconf information