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##### SUMMARY
If you don't have an ssh client installed in container image or on your system, ansible just throws following error -  `The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'` error. 

```
TASK [Gathering Facts] *********************************************************
[WARNING]: Unhandled error in Python interpreter discovery for host <hostname1>: [Errno 2] No such file or directory: b'ssh': b'ssh'

[WARNING]: Unhandled error in Python interpreter discovery for host <hostname2>: [Errno 2] No such file or directory: b'ssh': b'ssh'

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
fatal: [<hostname1>]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}

An exception occurred during task execution. To see the full traceback, use -vvv. The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
fatal: [<hostname2>]: FAILED! => {"msg": "Unexpected failure during module execution.", "stdout": ""}
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9.6
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
Run playbook on the system where ssh client is not installed & playbook is expecting to use ssh keys for remote hosts.


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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
If possible adding an error message indicating `ssh client is not installed on the system`

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Error message mentioned in the summary 
The error was: FileNotFoundError: [Errno 2] No such file or directory: b'ssh': b'ssh'
```

Thank you!!
timeout = 0
                    continue
                
                
                
                elif not selector.get_map():
                    p.wait()
                    break
                
        finally:
            selector.close()
            
            
            stdin.close()
            p.stdout.close()
            p.stderr.close()
        if C.HOST_KEY_CHECKING:
            if cmd[0] == b"sshpass" and p.returncode == 6:
                raise AnsibleError('Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support '
                                   'this.  Please add this host\'s fingerprint to your known_hosts file to manage this host.')
        controlpersisterror = b'Bad configuration option: ControlPersist' in b_stderr or b'unknown configuration option: ControlPersist' in b_stderr
        if p.returncode != 0 and controlpersisterror:
            raise AnsibleError('using -c ssh on certain older ssh versions may not support ControlPersist, set ANSIBLE_SSH_ARGS="" '
                               '(or ssh_args in [ssh_connection] section of the config file) before running again')
        
        
        controlpersist_broken_pipe = b'mux_client_hello_exchange: write packet: Broken pipe' in b_stderr
        if p.returncode == 255:
            additional = to_native(b_stderr)
            if controlpersist_broken_pipe: