使用GVM安装Groovy

$gvm install groovy
Stop! groovy is not a valid candidate.

为什么这不起作用？据我所知,我使用这个正确安装了GVM：

$curl -s get.gvmtool.net | bash

我在Mac上

这是我在运行gvm帮助时看到的内容：

$gvm help

Usage: gvm <command> <candidate> [version]
       gvm offline <enable|disable>

   commands:
       install   or i    <candidate> [version]
       uninstall or rm   <candidate> <version>
       list      or ls   <candidate>
       use       or u    <candidate> [version]
       default   or d    <candidate> [version]
       current   or c    [candidate]
       outdated  or o    [candidate]
       version   or v
       broadcast or b
       help      or h
       offline           <enable|disable>
       selfupdate        [force]
       flush             <candidates|broadcast|archives|temp>

   candidate  :
   version    :  where optional,defaults to latest stable if not provided

eg: gvm install groovy