Please don't abort the entire task when a file is missing

### Problem
I just enabled the bucket plugin and moving one directory at a time like this:

```
cd 2/
for x in * ;do beet move artist:"$x"; done
```
When beets traverses the individual artist directories and stumble upon an album with a missing track, the entire task is aborted. I would rather have beets complain and move on to the next album in the directory instead of simply bailing out:

```
Moving 13 items (3 already in place).
Error: No such file or directory while moving /mnt/music8/+TAGGED/2/2113 Pritt/2113 Pritt │2020│ Wrist Game 101 [MP3]/04 Ball 2.0.mp3 to /mnt/music8/+TAGGED/0-9/2113 Pritt/2113 Pritt │2020│ Wrist Game 101 [MP3]/04 Ball 2.0.mp3
Moving 40 items (19 already in place).
Error: No such file or directory while moving /mnt/music8/+TAGGED/2/213/213 │2004│ The Hard Way [CD, MP3]/01 Intro.1.mp3 to /mnt/music8/+TAGGED/0-9/213/213 │2004│ The Hard Way [CD, MP3]/01 Intro.mp3
Moving 24 items (5 already in place).
Error: No such file or directory while moving /mnt/music8/+TAGGED/2/21 Savage/21 Savage │2018│ I Am I Was [CD, MP3]/06 1.5.mp3 to /mnt/music8/+TAGGED/0-9/21 Savage/21 Savage │2018│ I Am I Was [CD, MP3]/06 1.5.mp3
```
The missing tracks are (mostly) files I have deleted like this:

```
find . -type f -regextype awk -iregex '.+[.][0-9][.](mp3|flac|jpg|m3u|ogg|m4a)' -delete
```
because they are duplicates and leftovers from previous imports.

Now, I know that I'm supposed to run a

``` beet update```
to reflect deleted files, however, I've had bad experiences with that in the past so I'm a bit nervous to do so again: https://github.com/beetbox/beets/discussions/3973

### Setup

* OS: Linux 5.19.6
* Python version: 3.9.4
* beets version: 1.5.0
* Turning off plugins made problem go away (yes/no): well, no

My configuration (output of `beet config`) is:

```yaml
# vim:synmaxcol=500:expandtab:fdm=marker:fdl=0:
# ${HOME}/etc/beets/config.yaml
# ‗‗‗‗‗‗‗‗‗‗‗‗ ‗‗‗‗‗‗ ‗‗‗‗‗‗‗‗ ‗‗‗‗‗‗‗‗‗‗‗
# owner Magnus Woldrich
# btime 2021-05-13 10:31:39
# mtime 2021-05-31 16:38:07
# permissions You are free to use things you may find useful here.
# Please improve and share.
# git http://github.com/trapd00r/configs/ (up-to-date)
# url http://japh.se
# irc japh@irc.libera.chat #vim #perl #beets
# ‗‗‗‗‗‗‗‗‗‗‗‗ ‗‗‗‗‗‗‗‗‗‗‗‗‗ ‗‗‗‗ ‗‗‗‗ ‗‗‗‗

#< what does it look like
## Alanis Morissette │2020│ Reckoning [Single, WEB, MP3]
## Alanis Morissette │2020│ Such Pretty Forks in the Road [WEB, FLAC]
## Anna Ternheim │2003│ My Secret [EP, CD, MP3]
## Anna Ternheim │2004│ Somebody Outside [CD, MP3]
## Anna Ternheim │2005│ Shoreline EP [EP, CD, MP3]
## ├── 01 Shoreline (radio Version).mp3
## ├── 02 Little Lies.mp3
## ├── 03 China Girl.mp3
## ├── 04 When Tomorrow Comes.mp3
## ├── 05 Anywhere I Lay My Head.mp3
## └── cover.jpg

## A/Anna Ternheim/Anna Ternheim │2003│ My Secret [EP, CD, MP3]
# '- 01 My Secret.mp3
# '- 02 All For Me.mp3
# '- 03 A Voice To Calm You Down.mp3
# '- 04 I Say No (gotland Version).mp3
# '- 05 Wedding Song (demo Version).mp3
# '- cover.jpg
#>

#< core options
directory: /mnt/music8/+TAGGED
library: ~/var/beets/beets202105.db
pluginpath: /usr/lib/python3.9/site-packages/beetsplug/

# files matching these patterns are deleted from source after import
clutter: ["Thumbs.DB", ".DS_Store", ".m3u", ".pls",
".jpg", ".nfo", ".txt", ".log", ".gif",
]

replace:
'[\\]': ''
'[_]': '-'
'[/]': '-'
'^\.': ''
'[\x00-\x1f]': ''
'[<>:"\?\*\|]': ''
'\.$': ''
'\s+$': ''
'^\s+': ''
'^-': ''

ignore: [".*", "*~", "System Volume Information"]

art_filename: cover # cover.jpg
#asciify_paths: yes
format_item: $path
per_disc_numbering: false
sort_album: path+
sort_case_insensitive: yes
sort_item: path+
threaded: yes
timeout: 5.0
verbose: no

#
#< plugins
#plugins: [ # mosaic
# 'fetchart', 'discogs', 'fromfilename', 'inline', 'smartplaylist',
# 'ftintitle', 'info', 'lastgenre', 'lastimport', 'thumbnails',
# 'mpdupdate', 'mpdstats', 'rewrite', 'duplicates', 'missing',
# 'extrafiles', 'edit', 'lyrics', 'mpdqueue',
#]

plugins: [
'bucket',
'discogs',
'duplicates',
# 'edit',
# 'extrafiles',
'fetchart',
'fromfilename',
'ftintitle',
'info',
'inline',
'lastgenre',
'lastimport',
# 'lyrics', # takes forever
# 'missing',
# 'mpdqueue',
# 'mpdstats',
'mpdupdate',
'rewrite',
# 'smartplaylist', # only run it once in a while
]

bucket:
bucket_alpha:
- '#-!'
- '0-9'
- 'A'
- 'B'
- 'C'
- 'D'
- 'E'
- 'F'
- 'G'
- 'H'
- 'I'
- 'J'
- 'K'
- 'L'
- 'M'
- 'N'
- 'O'
- 'P'
- 'Q'
- 'R'
- 'S'
- 'T'
- 'U'
- 'V'
- 'W'
- 'X'
- 'Y'
- 'Z'
bucket_alpha_regex:
'#-!': ^[^0-9a-zA-ZåÅäÄöÖ]
bucket_year: []
extrapolate: no

bpd:
host: 127.0.0.1
port: 6601

edit:
itemfields: track title artist album year
albumfields: track title artist albumartist album year

extrafiles:
patterns:
single_tracks:
- '+tracks/'
- '_tracks/'
single_live:
- '_live'
- '+live'
paths:
single_tracks: $artist/+tracks
single_live: $artist/+live

rewrite:
album .*Sommar i P1: P1 Sommar
album .*Sommar och Vinter i P1.*: P1 Sommar
album Söndagsintervjun: P1 Söndagsintervjun
album .*Musikguiden i p3: P3 Musikguiden
album Jukeboxen i p4: P4 Jukeboxen
album Musikspecial i p4: P4 Musikspecial
# albumartist Various Artists: VA
artist Pst.q: Pst-q
artist 10,000 Maniacs: 10000 Maniacs
artist Fronda.*: Fronda
artist Magnus Rytterstam.*: Magnus Rytterstam
artist 江海迦: Aga
artist Whoo Kid: DJ Whoo Kid
artist Looptroop.*: Looptroop
artist T.R: Öris
artist Organismen: Organism 12
artist Gms.*: GMS
artist (tupac|2[pP]ac).*: 2pac
artist .*weird Al.*: Weird Al Yankovic
artist .*Green Lantern.*: DJ Green Lantern
artist .ingenting.: Ingenting
artist Sin[eé]ad O.Connor.*: Sinéad O'Connor
artist .*Suzanne.*Vega: Suzanne Vega
artist .*1[23]00 mic.*: 1200 Micrograms
artist elin (ruth)? sigvardsson: Elin Sigvardsson
artist elin ruth: Elin Sigvardsson
artist ^Game$: The Game
artist ^Ken$: Ken Ring
artist Special D: Special D.
artist Danne W.*: Sjätte Sinnet
artist Sjatte Sinnet: Sjätte Sinnet
artist Ante Barazza: Sjätte Sinnet

mpd:
host: localhost
port: 6600
# music_directory: /mnt/music8

thumbnails:
auto: yes # default

lastfm:
user: betbot

lastgenre:
auto: yes # default
canonical: yes
force: no
source: artist

ftintitle:
auto: yes # default

smartplaylist:
# it's better to set save_absolute_paths_in_playlist option in mpd.conf
# relative_to: ~/mp3/
playlist_dir: ~/mp3/_playlists
playlists:
- name: '+all.m3u'
query: ''

- name: 'eminem.m3u'
query: 'artist:Eminem'

# - name: 'sm %lower{$genre}.m3u'
# query: ''

- name: '$year.m3u'
query: 'year::(199[0-9]|200[0-9]|201[0-9])'

- name: '+decent.m3u'
query: 'play_count:1..'

- name: '+wow.m3u'
query: 'play_count:5..'

- name: 'psychedelic'
query: 'genre:psychedelic'
- name: 'loved.m3u'
query: 'loved:1'

musicbrainz:
searchlimit: 10

missing:
format: "$path"

lyrics:
auto: yes
# fallback: ''

fetchart:
auto: yes
sources: coverart itunes amazon albumart wikipedia google

embedart:
auto: yes
#>
#< path setup
aunique:
disambuguators: media mastering label catalognum albumdisambig releasegroupdisambig

match:
preferred:
media: ['CD', 'Digital Media|File', 'Vinyl']

paths:
# mb_trackid::^$: +unmatched/
# https://www.japh.se/2021/05/23/custom-beet-path-rules-for-record-labels.html
# label:8bitpeoples: 8/8bitpeoples/%if{$hasyear,${year}} %title{$albumartist} - %title{$album}/${padded_tracknr} %title{$title}
tag:8bitpeoples: 0-9/8bitpeoples/%if{$hasyear,${year}} $first_artist - %title{$album}/${padded_tracknr} %title{$title}
label:whoa.nu: W/Whoa.nu/$base_name
label:rap_swe: +swe_hiphop/$base_name
label:randombastards: R/Randombastards/$base_name
label:Norrköping: S/Sjätte Sinnet/+tracks/$base_name
tag:rosamannen: +live/$artist - $album/$base_name
# tag:Rosamannen: +live/+rosamannen/$base_name
label:frizon.info: F/Frizon.info/$base_name
label:"Masters of Hardcore": M/Masters of Hardcore/$moh_catalog %if{$hasyear,${year}} %title{$album}/${padded_tracknr} %title{$artist} - %title{$title}
label:gamesoundtrack: +game/+ost/$album%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
label:ocremix: +game/+ocremix/$base_name
tag:overlooked: +game/+overlookedremix/$base_name
label:amigaremix: +game/+amigaremix/$base_name
# tag:gamealbums: +game/$first_artist - %title{$album}%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
tag:gamealbums: +game/%title{$album} [$albumartist]%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
# label:gamealbums: +game/$first_artist - %title{$album}%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
label:game: +game/+tracks/$base_name
tag:sr: +radio/Sveriges Radio/%title{$album}/%title{$title}
# label:radio: +radio/%title{$first_artist}/%title{$album}/%title{$title}
label:demo: %bucket{$first_artist, alpha}/%title{$first_artist}/+demo/$base_name
label:live: %bucket{$first_artist, alpha}/%title{$first_artist}/+live/%title{$albumartist}%if{$hasyear, │${year}│} %title{$album} [$alb_type$media_type$format]/${padded_tracknr} %title{$title}
# label:test: +test/%title{$artist}/%title{$album}/%title{$title}
# albumtype:mixtape: +mixtape/$mixtape_album [$first_artist]%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
tag:mixtape: +mixtape/$mixtape_album [$first_artist]%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
# albumtype:mixtape: +mixtape/$mixtape_album%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}
# default: %upper{%left{$albumartist,1}}/%title{$first_artist}/%title{$albumartist}%if{$hasyear, │${year}│} %title{$album} [$alb_type$media_type$format]/${padded_tracknr} %title{$title}
albumtype:soundtrack: +OST/%if{$hasyear,│${year}│}$album/${padded_tracknr} $artist - %title{$title}
default: %bucket{$albumartist, alpha}/%title{$first_artist}/%title{$albumartist}%if{$hasyear, │${year}│} %title{$album} [$alb_type$media_type$format]/${padded_tracknr} %title{$title}
comp: +VA/%title{$album}%if{$hasyear, (${year})}/${padded_tracknr} $artist - %title{$title}

# https://www.japh.se/2021/05/26/how-to-add-singletons-to-artist-dir-correctly-in-beets.html
singleton: %upper{%left{$artist,1}}/%title{$first_artist_singleton}/+tracks/$base_name

# I want bootlegs etc in the same setup as default
albumtype:other: %upper{%left{$albumartist,1}}/%title{$first_artist}/%title{$albumartist}%if{$hasyear, │${year}│} %title{$album} [$alb_type$media_type$format]/${padded_tracknr} %title{$title}
#>
#< inline fun!
item_fields:
# pad track number with zero if < 10
padded_tracknr: "'{:02n}'.format(track)"
moh_catalog: catalognum.replace(" ", "")

# capture first artist as primary artist to avoid directories like this:
# · B/Britney Spears/
# · B/Britney Spears feat Madonna/
# · B/Britney Spears vs Metallica/
# > https://github.com/beetbox/beets/issues/3176
# > https://www.japh.se/2021/06/01/capture-primary-artist-as-a-separate-field-in-beets.html
#
# handles:
# · Artist,
# · Artist &
# · Artist feat
# · Artist feat.
# · Artist featuring
# · Artist ft.
# · Artist vs
# · Artist vs.
# · Artist &
#
# The idea is to use $first_artist in the beginning of the path format
# like so:
#
# %title{$first_artist}/%title{$albumartist}
#
# which will put 'Jennifer Lopez feat. Pitbull' inside the main Jennifer
# Lopez directory, but still keep the feat. part in the directory name
# inside it.
#
# J/Jennifer Lopez Feat. Pitbull/Jennifer Lopez Feat. Pitbull │2012│ Dance Again [Single, WEB, MP3]/01 Dance Again.mp3
# -> J/Jennifer Lopez/Jennifer Lopez Feat. Pitbull │2012│ Dance Again [Single, WEB, MP3]/01 Dance Again.mp3

first_artist: |
import re
return re.split(',|\s+(feat(.?|uring)|&|(Vs|Ft).)', albumartist, 1, flags=re.IGNORECASE)[0]

first_artist_singleton: |
import re
return re.split(',|\s+(feat(.?|uring)|&|(Vs|Ft).)', artist, 1, flags=re.IGNORECASE)[0]

# file basename for singletons import - import as is, minus the extension.
base_name: |
import os.path
base = os.path.basename(path)
return os.path.splitext(base)[0]

album_fields:
mixtape_album: |
import re
album_fixed = album
return re.sub(r"G.unit Radio,?\s+(Pt|Part)[.]?\s*(.*)", r"G-Unit Radio \2", album_fixed, flags=re.IGNORECASE)

alb_status: |
# MB returns 4 values describing how "offical" a release is, they are:
# Official, Promotional, Bootleg, and Pseudo-Release
# We only note the middle two.
# https://musicbrainz.org/doc/Release#Status
if 'Promo' in albumstatus:
return 'Promo'
elif 'Bootleg' in albumstatus:
return 'Bootleg'
else:
return None
# Check if https://github.com/beetbox/beets/issues/2200 affects below
alb_type: |
alb_types = ""
albumtypes_list = {
'ep': 'EP, ',
'single': 'Single, ',
'live': 'Live, ',
'remix': 'Remix, ',
'dj-mix': 'DJ-mix, ',
'mixtape/street': 'Mixtape, ',
'interview': 'Interview, ',
}
for key, value in albumtypes_list.items():
if albumtype == key:
alb_types += str(value)
if alb_types is not None:
return alb_types
else:
return None

media_type: |
# https://musicbrainz.org/doc/Release/Format
# Lets Merge the variations of the same medium into the main medium name (Opinonated)
media_list = {
'12" Vinyl': 'VINYL, ',
'10" Vinyl': 'VINYL, ',
'7" Vinyl': 'VINYL, ',
'Cassette': 'CASSETTE, ',
'Digital Media': 'WEB, ',
'CD': 'CD, ',
'File': 'WEB, ',
}
# Lets omit these instead of converging them under a similar label like above (Opinonated)
media_types_to_omit = ['Enhanced CD', 'CDDA', 'Blu-spec CD', 'SHM-CD', 'HQCD', '']
if items[0].media in media_list:
return str(media_list[items[0].media])
elif items[0].media in media_types_to_omit:
return None
else:
return str(items[0].media)

hasyear: 1 if year > 0 else 0
#>
#< autotagger
# To control how tolerant the autotagger is of differences, use the
# strong_rec_thresh option, which reflects the distance threshold below
# which beets will make a “strong recommendation” that the metadata
# be used.
#
# default is 0.04
match:
strong_rec_thresh: 0.10
medium_rec_thresh: 0.25
ignored: missing_tracks unmatched_tracks
ignored_media: ['Data CD', 'DVD', 'DVD-Video', 'Blu-ray', 'HD-DVD',
'VCD', 'SVCD', 'UMD', 'VHS']
#>
#< ui
ui:
color: yes
colors:
text_success: green
text_warning: yellow
text_error: red
text_highlight: blue
text_highlight_minor: lightgray
action_default: turquoise
action: blue
#>

```