phpcd.vim: A lot of errors

VIM version: 7.4.52 (using SPF13 distribution) PHP 7.0.23

I installed this with Vundle: Plugin 'lvht/phpcd.vim', ran BundleInstall then opened a php file. I immediately got this error:

Error detected while processing function rpc#start:
line    4:
E117: Unknown function: job_start
E15: Invalid expression: job_start(a:000, {'out_cb': function('s:OnCall'), 'err_cb': function('s:OnError2')})
Press ENTER or type command to continue

I thought this might have had something to do with PCNTL missing, but I verified that it’s installed with this:

➜  ~ php --info | ag pcntl
pcntl
pcntl support => enabled
➜  ~ 

When I try to Ctrl+] then I get a ton of errors. This is in a project with composer.