`reflink: auto` makes `convert` plugin crash on btrfs

Problem

There seems to be problem with reflink and convert because it uses /tmp where it's not necessary the same actual btrfs filesystem

I wanted to convert all my files to .opus on import. I have btrfs, so of course i wanted to use reflink goodies

Documentation said that reflink: auto will use reflink if filesystem supports it. However, i have a feeling like there is some global flag ala:

if options['reflink'] == 'auto' and fs in ['btrfs', ...]:
    useReflinks = True  # now it will *always* do cp --reflink=always ...

because when all my imported files where done encoding:

...
convert: Finished encoding /home/matiii/Downloads/1-800-OŚWIECENIE/23 Niedziela.opus
convert: Finished encoding /home/matiii/Downloads/1-800-OŚWIECENIE/25 Main Stage Freestyle.opus
Error: OS/filesystem does not support reflinks. during link of paths /tmp/tmpofeiyiwv.opus, /home/matiii/Music/beets/Taco Hemingway/1‐800‐OŚWIECENIE/01 #1 – WIELKOMIEJSKA BEZSENNOŚĆ.opus
matiii@matiii $

This will also happen if i manually do:

cp --reflink /tmp/tmpofeiyiwv.opus /home/matiii/Music/beets/Taco\ Hemingway/1‐800‐OŚWIECENIE/bez.opus
cp: failed to clone '/home/matiii/Music/beets/Taco Hemingway/1‐800‐OŚWIECENIE/bez.opus' from '/tmp/tmpofeiyiwv.opus': Invalid cross-device link
# or:
cp --reflink=always ... # same error

seems like my /tmp/ may be in-ram or something (i didn't customize it in fstab or anything :shrug:)

When i do:

cp --reflink=auto /tmp/tmpofeiyiwv.opus /home/matiii/Music/beets/Taco\ Hemingway/1‐800‐OŚWIECENIE/bez.opus
matiii@matiii $ # works well!

Setup

OS: Arch Linux x86_64 - 6.11.3-arch1-1
Python version: 3.12.7
beets version: ~~1.6.1~~ 2.0.0 apparently
Turning off plugins made problem go away (yes/no): ummm... technically yeah xD

My configuration (output of beet config) is:

import:
  write: yes
  move: no
  reflink: auto
  autotag: yes

...

convert:
  auto: yes
  max_bitrate: 96
  format: opus

beetbox / beets

`reflink: auto` makes `convert` plugin crash on btrfs #5484

Problem

Setup