Please describe the problem.
We use httpalso for public read-only access to an ssh writable remote storing many datasets (this uses datalad ria-store, but that's a detail here).
That works flawlessly on linux, but a windows user recently reported that they couldn't download the data.
As I had some linux "deploy" tests on that dataset (mainly datalad install and fsck --fast from special remotes), I managed after wrestling with windows actions setup to run an equivalent on windows and I am able to reproduce the bug.
As I don't have a windows VM that was the simplest and more long-term way to ensure that works.
It seems httpalso on Windows malforms the path in the URLs, see the troubleshooting actions job here https://github.com/courtois-neuromod/algonauts_2025.competitors/actions/runs/13502500268/job/37724172008
The path in the URL is /users/cneuromod/ria-conp/5d2/0a1ae-3571-4de8-94c8-8ddb416cd3b0/annex/objects/xw%5CXV%5C/MD5E-s105090--c62dbfef65f486c626c10f778ebbe4f2.nii.gz/MD5E-s105090--c62dbfef65f486c626c10f778ebbe4f2.nii.gz where xw%5CXV%5C should be something like xw/XV so some conversion of the windows backslash to posix might not be working.
(httpalso also fallbacks to an URL assuming all objects are flat in annex/objects, but that obviously fails as this is not stored that way in the remote.)
What steps will reproduce the problem?
git-annex get a file from a httpalso special remote on a windows machine.
The dataset https://github.com/courtois-neuromod/algonauts_2025.competitors can be used for troubleshooting as this is fully public (git+annex).
What version of git-annex are you using? On what operating system?
10.20250115 on windows
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
# 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)
Yes, our whole data management relies on git-annex and datalad! Thanks for that amazing tool!
That was a good analysis, thanks!
I see that Remote.HttpAlso.supportedLayouts uses hashDirLower and hashDirMixed. Which are implemented using OS-native path separators. So, on Windows, that does come out with the slash the wrong way around. I don't think that the actual url-encoding of it is problimatic.
I've put in a workaround. I have not tested on windows, so please re-open this bug report if you upgrade and find it still somehow doesn't work.