vf projeto em casca de peixe

Question

Estou usando o peixe virtual no fish shell, portanto, ao tentar fazer o vf project projectName , ele gera o erro abaixo:

vf project pytube

fish: Unknown command 'virtualenv'
/Users/userName/clones/virtualfish/virtual.fish (line 152):     virtualenv $argv $VIRTUALFISH_HOME/$envname
                                                                        ^
in function '__vf_new',
    called on line 52 of file '/Users/userName/clones/virtualfish/virtual.fish',
    with parameter list 'pytube'

in . (source) call of file '-',
    called on line 85 of file '/Users/userName/clones/virtualfish/virtual.fish',

in function 'vf',
    called on line 43 of file '/Users/userName/clones/virtualfish/projects.fish',
    with parameter list 'new pytube'

in function '__vf_project',
    called on line 52 of file '/Users/userName/clones/virtualfish/virtual.fish',
    with parameter list 'pytube'

in . (source) call of file '-',
    called on line 85 of file '/Users/userName/clones/virtualfish/virtual.fish',

in function 'vf',
    called on standard input,
    with parameter list 'project pytube'

Error: The virtualenv wasn't created properly.
virtualenv returned status 127.

Estou usando o OSx onde estou recebendo este erro.