Well, I know that my setup is "experimental" - I am trying to establish consistent conda environment, ATM everything (git and all the posix tools) come from conda (conda-forge channel at large) and then git-annex is installed on top - pretty much simply extracted into conda environment from our git-annex-installer.exe built with magic.

Running (in a windows shell, so not in bash)

(datalad-2) C:\Users\DataLad\AppData\Local\Temp\datalad_temp_tree_hufbz7i1>git add --verbose "fi le2.dat"
git-annex smudge --clean -- 'fi le2.dat': git-annex: command not found
error: external filter 'git-annex smudge --clean -- %f' failed 127
error: external filter 'git-annex smudge --clean -- %f' failed
add 'fi le2.dat'

suggests that git does see git-annex, but then git-annex smudge doesn't see git-annex in the PATH?

(datalad-2) C:\Users\DataLad\AppData\Local\Temp\datalad_temp_tree_hufbz7i1>echo %PATH%
C:\Users\DataLad\miniconda3\envs\datalad-2;C:\Users\DataLad\miniconda3\envs\datalad-2\Library\mingw-w64\bin;C:\Users\DataLad\miniconda3\envs\datalad-2\Library\usr\bin;C:\Users\DataLad\miniconda3\envs\datalad-2\Library\bin;C:\Users\DataLad\miniconda3\envs\datalad-2\Scripts;C:\Users\DataLad\miniconda3\envs\datalad-2\bin;C:\Users\DataLad\miniconda3\condabin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files\Git\cmd;C:\Users\DataLad\AppData\Local\Microsoft\WindowsApps;.

and there is C:\Users\DataLad\miniconda3\envs\datalad-2\Library\bin\git-annex.exe .

(datalad-2) C:\Users\DataLad\AppData\Local\Temp\datalad_temp_tree_hufbz7i1>git annex version
git-annex version: 8.20201008-g3be4731
build flags: Assistant Webapp Pairing TorrentParser MagicMime Feeds Testsuite S3 WebDAV
dependency versions: aws-0.22 bloomfilter-2.0.1.0 cryptonite-0.26 DAV-1.3.4 feed-1.3.0.1 ghc-8.8.4 http-client-0.6.4.1 persistent-sqlite-2.10.6.2 torrent-10000.1.1 uuid-1.3.13 yesod-1.6.1.0
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 X*
remote types: git gcrypt p2p S3 bup directory rsync web bittorrent webdav adb tahoe glacier ddar git-lfs httpalso hook external
operating system: mingw32 x86_64
supported repository versions: 8
upgrade supported from repository versions: 2 3 4 5 6 7
local repository version: 8

notabug --Joey