Carthage not found


Hey, guys.

I have trouble with carthage.
I use carthage to import frameworks, so I call carthage(platform: 'iOS') within my Fastfile.
But it returns error message as below.
No such file or directory - carthage
so I typed to confirm carthage location which carthage, but it returns

carthage update returned exit code 127

bash: line 1: carthage: command not found Action failed: carthage update

It looks like CircleCI bug, so I reported this.