Please describe the problem.

Different git-annex operations in a repository initialized with git init --object-format=sha256 produce an error message of the form fatal: ambiguous argument '4b825dc642cb6eb9a060e54bf8d69288fbee4904': unknown revision or path not in the working tree..

What steps will reproduce the problem?

See transcript below, which produces the error message on git annex add and git annex get.

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

git-annex version: 10.20240927-g3d7f94ea398b5e84dab3bc89bc5b37746de1d40c
build flags: Assistant Webapp Pairing Inotify DBus DesktopNotify TorrentParser MagicMime Servant Benchmark Feeds Testsuite S3 WebDAV
dependency versions: aws-0.24.1 bloomfilter-2.0.1.2 crypton-0.33 DAV-1.3.4 feed-1.3.2.1 ghc-9.4.7 http-client-0.7.14 persistent-sqlite-2.13.2.0 torrent-10000.1.3 uuid-1.3.15 yesod-1.6.2.1
key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_224 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 BLAKE2B256E BLAKE2B256 BLAKE2B512E BLAKE2B512 BLAKE2B160E BLAKE2B160 BLAKE2B224E BLAKE2B224 BLAKE2B384E BLAKE2B384 BLAKE2BP512E BLAKE2BP512 BLAKE2S256E BLAKE2S256 BLAKE2S160E BLAKE2S160 BLAKE2S224E BLAKE2S224 BLAKE2SP256E BLAKE2SP256 BLAKE2SP224E BLAKE2SP224 SHA1E SHA1 MD5E MD5 WORM URL GITBUNDLE GITMANIFEST VURL X*
remote types: git gcrypt p2p S3 bup directory rsync web bittorrent webdav adb tahoe glacier ddar git-lfs httpalso borg rclone hook external
operating system: linux x86_64
supported repository versions: 8 9 10
upgrade supported from repository versions: 0 1 2 3 4 5 6 7 8 9 10
local repository version: 10

Please provide any additional information below.

# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log

$ mkdir test-sha256
$ cd test-sha256
$ git init --object-format=sha256
Initialized empty Git repository in /home/icg149/Playground/test-sha256/.git/
$ git annex init
init  ok
(recording state in git...)
$ echo test123 > 123.txt
$ git annex add 123.txt
add 123.txt 
100%  8 B              27 KiB/s 0sfatal: ambiguous argument '4b825dc642cb6eb9a060e54bf8d69288fbee4904': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
ok                                
(recording state in git...)
$ git commit -m "Add file"
[main (root-commit) 32fdb51] Add file
 1 file changed, 1 insertion(+)
 create mode 120000 123.txt
$ ls -l
total 4
lrwxrwxrwx 1 icg149 icg149 186 Okt  8 09:10 123.txt -> .git/annex/objects/05/GP/SHA256E-s8--9572d7f4e812df12cd8c0d26e7308864c33cbb51b004cbe962ad545bc377a4a2.txt/SHA256E-s8--9572d7f4e812df12cd8c0d26e7308864c33cbb51b004cbe962ad545bc377a4a2.txt
$ cd ..
$ git clone test-sha256/ test-sha256-clone
Cloning into 'test-sha256-clone'...
done.
$ cd test-sha256-clone
$ git annex get .
get 123.txt (from origin...) 
fatal: ambiguous argument '4b825dc642cb6eb9a060e54bf8d69288fbee4904': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
ok
(recording state in git...)

# End of transcript or log.

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)