bash completion broken on MacOS & bash < 4.4

[milo-minderbinder]

Issue description

Since #4849 was merged, bash completion is no longer available for bash bundled with MacOS (bundled version is 3.2) and other environments where installed bash version < 4.4, due to the minimum bash version requirement described in the first line of the click docs here: https://click.palletsprojects.com/en/8.0.x/shell-completion/.

Expected result

Bash completion would continue to work on standard MacOS environments.

Actual result

Bash completion support is broken on MacOS with bundled bash:

Steps to replicate

$ uname -mprsv
Darwin 20.6.0 Darwin Kernel Version 20.6.0: Tue Oct 12 18:33:42 PDT 2021; root:xnu-7195.141.8~1/RELEASE_X86_64 x86_64 i386
$ bash --version
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin20)
Copyright (C) 2007 Free Software Foundation, Inc.
$ pipenv --version
pipenv, version 2021.11.9
$ eval "$(_PIPENV_COMPLETE=bash_source pipenv)"
Traceback (most recent call last):
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/bin/pipenv", line 8, in <module>
    sys.exit(cli())
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv/vendor/click/core.py", line 1137, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv/vendor/click/core.py", line 1057, in main
    self._main_shell_completion(extra, prog_name, complete_var)
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv/vendor/click/core.py", line 1132, in _main_shell_completion
    rv = shell_complete(self, ctx_args, prog_name, complete_var, instruction)
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv/vendor/click/shell_completion.py", line 45, in shell_complete
    echo(comp.source())
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv/vendor/click/shell_completion.py", line 324, in source
    self._check_version()
  File "/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv/vendor/click/shell_completion.py", line 312, in _check_version
    raise RuntimeError(
RuntimeError: Shell completion is not supported for Bash versions older than 4.4.

---

$ pipenv --support

Pipenv version: '2021.11.9'

Pipenv location: '/usr/local/Cellar/pipenv/2021.11.9/libexec/lib/python3.10/site-packages/pipenv'

Python location: '/usr/local/Cellar/pipenv/2021.11.9/libexec/bin/python3.10'

Python installations found:

• 3.9.7: /usr/local/bin/python3
• 3.9.7: /usr/local/bin/python3.9
• 3.9.5: /Users/milo/.pyenv/versions/3.9.5/bin/python3
• 3.8.12: /Users/milo/.pyenv/versions/3.8.12/bin/python3
• 3.8.9: /usr/bin/python3
• 3.7.11: /Users/milo/.pyenv/versions/3.7.11/bin/python3
• 2.7.16: /usr/bin/python
• 2.7.16: /usr/bin/python2
• 2.7.16: /usr/bin/python2.7
• 2.7.2: /usr/local/bin/jython

PEP 508 Information:

{'implementation_name': 'cpython',
 'implementation_version': '3.10.0',
 'os_name': 'posix',
 'platform_machine': 'x86_64',
 'platform_python_implementation': 'CPython',
 'platform_release': '20.6.0',
 'platform_system': 'Darwin',
 'platform_version': 'Darwin Kernel Version 20.6.0: Tue Oct 12 18:33:42 PDT '
                     '2021; root:xnu-7195.141.8~1/RELEASE_X86_64',
 'python_full_version': '3.10.0',
 'python_version': '3.10',
 'sys_platform': 'darwin'}

System environment variables:

• PATH
• NVM_INC
• TERM_PROGRAM
• PYENV_ROOT
• NVM_CD_FLAGS
• M2
• SHELL
• TERM
• SHELLCHECK_OPTS
• TMPDIR
• GRADLE_HOME
• TERM_PROGRAM_VERSION
• TERM_SESSION_ID
• ANSIBLE_VAULT_PASSWORD_FILE
• NVM_DIR
• JRE_HOME
• USER
• HUSKY_SKIP_INSTALL
• SSH_AUTH_SOCK
• JAVA7
• JAVA8
• BASH_SILENCE_DEPRECATION_WARNING
• WORKON_HOME
• OLD_PS1
• _
• __CFBundleIdentifier
• PWD
• HOMEBREW_GITHUB_API_TOKEN
• JAVA_HOME
• EDITOR
• LANG
• XPC_FLAGS
• XPC_SERVICE_NAME
• GPG_TTY
• PYENV_SHELL
• M2_HOME
• SHLVL
• HOME
• GOROOT
• JAVA11
• LOGNAME
• GROOVY_HOME
• JAVA17
• NVM_BIN
• GOPATH
• ANSIBLE_CONFIG
• LPASS_CLIPBOARD_COMMAND
• __CF_USER_TEXT_ENCODING
• PIP_SHIMS_BASE_MODULE
• PIP_DISABLE_PIP_VERSION_CHECK
• PYTHONDONTWRITEBYTECODE
• PIP_PYTHON_PATH
• PYTHONFINDER_IGNORE_UNSUPPORTED

Pipenv–specific environment variables:

Debug–specific environment variables:

• PATH: /usr/local/Cellar/pipenv/2021.11.9/libexec/tools:/Users/milo/.pyenv/shims:/Users/milo/.nvm/versions/node/v16.13.0/bin:/Users/milo/go/bin:/usr/local/opt/go/libexec/bin:/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
• SHELL: /bin/bash
• EDITOR: /usr/local/bin/vim
• LANG: en_US.UTF-8
• PWD: /Users/milo

---

[frostming]

Not much Pipenv can do here, as long as we depend on click to provide completion.