Goo Truther 
downloading wikipedia
extracting wikipedia
extracting wikipedia
Process engrampa dumped core, coredump file size on disk 1G.
Engrampa seems to trigger a segfault when giving me file listings of the the contents of the root folder, not even the "articles" directory.
extracting wikipedia
file roller is next to bat, and I am able to list the /en/ directory within root, but I've been stuck loading the file listing for articles/ with a severe CPU bottleneck and 5GB of disk reads queued up in memory waiting to see Dr. CPU. No more I/O on the disk containing wikipedia for the past... 10 minutes? At least it isn't crashing? A slimegirl can hope.
extracting wikipedia
So everything graphical uses tar wrong. And just doing it manually works, but I have to have enough disk space to extract the tar from within the 7zip archive as a result. Around 200GB before final extraction, just to get started.
extracted wikipedia
English is like 247ish GB, but you need about twice that to actually extract any of it at all. Nothing can handle file listings this big.