Please describe the problem.

git annex add is not fully compatible with multibyte-characters in filenames and may generate filenames with invalid character sequences.

What steps will reproduce the problem?

$ git init test; cd test
$ git annex init test
$ echo bla > 01-06\ 三石琴乃・富沢美智恵・久川綾・篠原恵美・深見梨加\ -\ Tuxedo\ Mirage.flac
$ git annex add 01*

The last command generates an invalid character sequence as filename which, depending on the filesystem, may cause an error:

Example output:

add "01-06 \344\270\211\347\237\263\347\220\264\344\271\203\343\203\273\345\257\214\346\262\242\347\276\216\346\231\272\346\201\265\343\203\273\344\271\205\345\267\235\347\266\276\343\203\273\347\257\240\345\216\237\346\201\265\347\276\216\343\203\273\346\267\261\350\246\213\346\242\250\345\212\240 - Tuxedo Mirage.flac"
  .git/annex/othertmp/: openTempFile template ingest-01-06 三石琴乃・富沢美智恵・久川綾・篠原恵美・深見梨�: invalid argument (Invalid or incomplete multibyte or wide character)

failed
add: 1 failed

What version of git-annex are you using? On what operating system?

git annex 10.20250630 NixOS 25.11pre851350.3b9f00d7a7bf

Please provide any additional information below.

Creation of the file fails due to zfs being set to only accept valid utf-8 filenames (utf8only=on, normalization=formD), which greatly helps me detecting encoding issues in filenames. The original file obviously has a correct encoding, but it seems that git annex generates a new filename by just cutting of the filename after a specific byte, instead of taking character lengths into account.

Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

I use git annex to manage my whole music collection successfully.

fixed --Joey