Semgrep crashes when working directory doesn't exist

[underyx]

My shell was in a temporary directory that has been deleted since I cd'd in there. Running semgrep failed with this:

❯ semgrep -e 'echo' -l bash ~/r2c/semgrep/.github/post-checkout
Traceback (most recent call last):
  File "/opt/homebrew/bin/semgrep", line 33, in <module>
    sys.exit(load_entry_point('semgrep==0.84.0', 'console_scripts', 'semgrep')())
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/semgrep/__main__.py", line 20, in main
    cli()
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/click/core.py", line 1128, in __call__
    return self.main(*args, **kwargs)
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/click/core.py", line 1053, in main
    rv = self.invoke(ctx)
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/click/core.py", line 1659, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/click/core.py", line 1395, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/click/core.py", line 754, in invoke
    return __callback(*args, **kwargs)
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/semgrep/commands/scan.py", line 816, in scan
    ) = semgrep.semgrep_main.main(
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/semgrep/semgrep_main.py", line 298, in main
    all_rules = configs_obj.get_rules(no_rewrite_rule_ids)
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/semgrep/config_resolver.py", line 312, in get_rules
    self._rename_rule_ids(configs)
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/semgrep/config_resolver.py", line 347, in _rename_rule_ids
    f"{Config._convert_config_id_to_prefix(config_id)}{rule.id or MISSING_RULE_ID}"
  File "/opt/homebrew/Cellar/semgrep/0.84.0/libexec/lib/python3.10/site-packages/semgrep/config_resolver.py", line 335, in _convert_config_id_to_prefix
    at_path = Config._safe_relative_to(at_path, Path.cwd())
  File "/opt/homebrew/Cellar/python@3.10/3.10.2/Frameworks/Python.framework/Versions/3.10/lib/python3.10/pathlib.py", line 991, in cwd
    return cls(cls._accessor.getcwd())
FileNotFoundError: [Errno 2] No such file or directory

so to reproduce:

1. mkdir temp
2. cd temp
3. (in another shell) rm temp
4. (in first shell) run semgrep

using semgrep 0.84

[r2c-demo]

This issue is synced in Linear at https://linear.app/r2c/issue/PA-951/semgrep-crashes-when-working-directory-doesnt-exist.

[IagoAbal]

Closed by #5548.