gom install with :command

[jheroy]

gom file:

gom 'git.xxx.com/xx/pfsdk', :command => 'git clone [email protected]:xx/pfsdk'

First time i exec gom install ,it works fine, but i exec it again ,it report an error:
fatal: destination path '/path/to/_vendor/src/git.xxx.com/xx/pfsdk' already exists and is not an empty directory

[mattn]

syntax :command => is not supported yet.