I know. I will use --depth 1 !
$ git clone --depth 1
https://gerrit.wikimedia.org/r/p/mediawiki/core.git mediawiki
Cloning into 'mediawiki'...
error: RPC failed; result=22, HTTP code = 500
fatal: The remote end hung up unexpectedly
$ git clone --depth 2
https://gerrit.wikimedia.org/r/p/mediawiki/core.git mediawiki
Cloning into 'mediawiki'...
error: RPC failed; result=22, HTTP code = 500
fatal: The remote end hung up unexpectedly
$ git clone --depth 0
https://gerrit.wikimedia.org/r/p/mediawiki/core.git mediawiki
Cloning into 'mediawiki'...
remote: Counting objects: 356168, done
remote: Finding sources: 100% (356168/356168)
Receiving objects: 8% (29137/356168), 6.38 MiB | 112 KiB/s
I don't really know what --depth 0 will get me. Fingers crossed.