I ran this overnight last night (well, technically it’s still running, in the “writing objects” phase). I got a lot of messages of the form
warning: unable to access ‘packages/Pootle/Pootle-2.7.0.tar.bz2/Pootle-2.7.0/pootle/static/js/node_modules/webpack/node_modules/watchpack/node_modules/chokidar/node_modules/anymatch/node_modules/micromatch/node_modules/regex-cache/node_modules/is-equal-shallow/.gitattributes’: Filename too long
This is on Windows. Having done some research, it looks like you not only need the “Enable long paths” setting switched on (which is documented in the Python setup docs and I believe can be done in the Python installer) but you also need to set core.longpaths in git’s configuration.
I haven’t tested core.longpaths yet, as the initial download is still running (and I don’t know if I’ll need to do it again!) but the linked StackOverflow question mentions “some limitations”, so it may have problems…