Ucoin binary procedure

I got problems :

➜  ucoin-v0.12  curl -kL https://github.com/ucoin-io/ucoin/releases/download/v0.12-beta2/ucoin.tar.gz | tar xz -C ucoin-v0.12
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   588    0   588    0     0    844      0 --:--:-- --:--:-- --:--:--   844
  0 24.4M    0     0    0     0      0      0 --:--:--  0:00:01 --:--:--     0tar: ucoin-v0.12 : open impossible: Aucun fichier ou dossier de ce type
tar: Error is not recoverable: exiting now
curl: (23) Failed writing body (1444 != 16384)

So I used wget to download and extract it but I get :

➜  ucoin-v0.12  ./node/bin/node --version
v0.12.8
➜  ucoin-v0.12  ./ucoin                  
Node.js v0.12 is not available

I'm using archlinux 64 bits and zshrc as a shell.