cache:clear arguments are confusing

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Windows 10
• Poetry version: 0.12.2

Issue

poetry cache:clear --help
Usage:
  cache:clear [options] [--] <cache>

Arguments:
  cache                           The name of the cache to clear.

Options:
      --all                       Clear all caches.
  -h, --help                      Display this help message
  -q, --quiet                     Do not output any message
  -V, --version                   Display this application version
      --ansi                      Force ANSI output
      --no-ansi                   Disable ANSI output
  -n, --no-interaction            Do not ask any interactive question
  -v|vv|vvv, --verbose[=VERBOSE]  Increase the verbosity of messages: 1 for normal output, 2 for more verbose output and 3 for debug

Help:
 Clears poetry's cache.

It reads as if --all and cache name are mutually exclusive (instead of clearing the named cache, I clear all caches) but when I do poetry cache:clear --all

poetry cache:clear --all -vvv

[MissingArguments]
Not enough arguments

Exception trace:
 C:\Users\epage.AMER\AppData\Roaming\.poetry\lib\poetry\_vendor\py2.7\cleo\application.py in run() at line 94
   status_code = self.do_run(input_, output_)
 C:\Users\epage.AMER\AppData\Roaming\.poetry\lib\poetry\console\application.py in do_run() at line 88
   return super(Application, self).do_run(i, o)
 C:\Users\epage.AMER\AppData\Roaming\.poetry\lib\poetry\_vendor\py2.7\cleo\application.py in do_run() at line 197
   status_code = command.run(input_, output_)
 C:\Users\epage.AMER\AppData\Roaming\.poetry\lib\poetry\console\commands\command.py in run() at line 77
   return super(BaseCommand, self).run(i, o)
 C:\Users\epage.AMER\AppData\Roaming\.poetry\lib\poetry\_vendor\py2.7\cleo\commands\base_command.py in run() at line 141
   input_.validate()
 C:\Users\epage.AMER\AppData\Roaming\.poetry\lib\poetry\_vendor\py2.7\cleo\inputs\input.py in validate() at line 68
   raise MissingArguments('Not enough arguments')

cache:clear [--all] [--] <cache>

[macedigital]

Just for completeness, this issue is not resolved, nor just a documentation issue.

OS: Ubuntu 18.04.4 LTS Poetry: 1.0.3

$ poetry --version 
Poetry version 1.0.3

$ poetry cache clear -- --all 
[RuntimeError]
Add the --all option if you want to clear all --all caches

$ poetry cache clear --all 
Not enough arguments (missing: "cache").

“Accepted” solution:

$ poetry cache:clear --all 
The command "cache:clear" is not defined.

$ poetry cache clear pypi --all
Delete 791 entries? (yes/no) [no] yes

[epage]

As a user, this is a bit frustrating for issues to be automatically closed when the problem is unresponsiveness from the maintainers.