Update installation instructions for OS X

[tamaracha]

I have added Datalad to the Homebrew package manager and updated the installation docs for OS X accordingly. The datalad formula installs git-annex as dependency, and gets Datalad via pip.

[bpoldrack]

I have added Datalad to the Homebrew package manager

Awesome, thank you!

Do you mind pointing that out in the handbook, too? https://github.com/datalad-handbook/book

Ping @adswa

[adswa]

I have added Datalad to the Homebrew package manager

That's fantastic! Thank you! I can add it to the handbook later, unless someone beats me to it :)

[tamaracha]

Thanks for the quick merge. Yes, I can update the installation instructions for MacOS in the handbook now. Perhaps, it can be shortened a bit, because it is almost impossible to install homebrew without visiting their installation docs. ;-)

[adswa]

Ah, I was a minute ahead, sorry! I've just added a PR here: https://github.com/datalad-handbook/book/pull/675 Would you mind reviewing it? :) There is also a preview here: https://datalad-handbook--675.org.readthedocs.build/en/675/intro/installation.html#macos-osx I would be particular grateful if you could check that it is correct that p7zip needs a separate installation as a last step.

[adswa]

(If you started working on a PR already, please push and PR it, I wouldn't want your work to be in vain - I just didn't see you comment until a few minutes ago)

[tamaracha]

No problem. ;-) I was still collecting links and learning RST (I prefer markdown). I still didn't have any issues concerning missing 7zip, but I can test it and add it to my homebrew formula as dependency like git-annex.

[adswa]

I still didn't have any issues concerning missing 7zip, but I can test it and add it to my homebrew formula as dependency like git-annex.

This would be great, thank you!

[tamaracha]

Do you know which commands should fail, if 7zip is needed?

[tamaracha]

datalad save works, e.g.

[adswa]

Its not relevant for most commands, only a small set of functionality requires it. It would also warn about a missing external dependency as far as I know. ORA remotes and RIA stores use it sometimes and datalad download-url --archive, I think. Browsing through my shell history, the only command that comes up is

$ datalad create abc && cd abc
$  datalad download-url \                                                                                      
     --archive \
     --message "Download Imagenette dataset" \
     'https://s3.amazonaws.com/fast-ai-imageclas/imagenette2-160.tgz'

(its a somewhat sizable archive (a few hundred MB?), any other archive would work as a test, too)

[adswa]

as a test maybe: datalad download-url --archive -m test https://www.7-zip.org/a/7za920.zip

[tamaracha]

OK, that sounds more like an edge case. Your second test works because it is a conventional zip file. ;-) Your first file seems to be an ordinary tgz archive, no 7-zip either. I created a 7z file myself and can confirm that datalad needs a suitable executable to extract 7z archives. I suggest to add p7zip as optional (opt-in) or recommended (opt-out) dependency to my formula. In the docs, it can be pointed out that you need 7-zip, if you intend to extract 7z archives.