Fix shell auto-completion

[JeanChristopheMorinPerso]

Auto completion in shells was broken by the last update of argcomplete we did in 2025. This PR fixes that and also adds a test to make sure we don't regress on this anymore in the future.

Autocomplete was also broken on Python 3.12, which requires a newer argcomplete version. So I also updated argcomplete.

Note that the tests have been AI generated. You can see my LLM session at https://ampcode.com/threads/T-019debb1-9b44-75c1-b786-0ff399afec9e. I also create a follow-up session to get even more coverage: https://ampcode.com/threads/T-019debfb-1e29-772e-8d45-6f613e7a25aa. Total cost is $15 US.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.68%. Comparing base (39eeabe) to head (83077cb).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2091      +/-   ##
==========================================
+ Coverage   59.91%   60.68%   +0.76%     
==========================================
  Files         164      164              
  Lines       20557    20561       +4     
  Branches     3571     3570       -1     
==========================================
+ Hits        12317    12477     +160     
+ Misses       7370     7215     -155     
+ Partials      870      869       -1     

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[Copilot]

Pull request overview

This PR updates Rez’s vendored argcomplete and related shell integration to restore working shell auto-completion (including Python 3.12), and adds regression tests to prevent future breakage.

Changes:

• Bump vendored argcomplete to 3.6.3 and update multiple integration points (shell code generation, finders/lexing, argparse introspection, global completion loader).
• Add vendored argcomplete helper scripts for registration and global activation.
• Add CLI completion regression tests covering both argcomplete.autocomplete() and Rez’s _rez-complete entry point.

Reviewed changes

Copilot reviewed 2 out of 15 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/rez/vendor/README.md	Updates vendored argcomplete version metadata/date.
src/rez/vendor/argcomplete/shell_integration.py	Updates generated bash/zsh/fish completion shellcode and script handling.
src/rez/vendor/argcomplete/scripts/register_python_argcomplete.py	Adds vendored register-python-argcomplete helper script.
src/rez/vendor/argcomplete/scripts/python_argcomplete_check_easy_install_script.py	Adds vendored easy_install wrapper check script.
src/rez/vendor/argcomplete/scripts/activate_global_python_argcomplete.py	Adds vendored global activation helper.
src/rez/vendor/argcomplete/packages/_shlex.py	Tracks last wordbreak position for quoting/ltrim logic.
src/rez/vendor/argcomplete/packages/_argparse.py	Updates argparse introspection for newer Python tuple shapes/signatures.
src/rez/vendor/argcomplete/finders.py	Refactors debug stream init, help expansion, quoting/escaping behavior.
src/rez/vendor/argcomplete/completers.py	Adjusts completer base typing and bash compgen workaround.
src/rez/vendor/argcomplete/bash_completion.d/_python-argcomplete	Updates global completion loader logic for zsh/bashed usage.
src/rez/vendor/argcomplete/_check_module.py	Updates module resolution logic for python -m ... marker checks.
src/rez/vendor/argcomplete/_check_console_script.py	Updates console_script entry point lookup for Python 3.12+.
src/rez/tests/test_cli.py	Adds regression tests for subcommand/option completion behavior.
src/rez/cli/_complete_util.py	Updates RezCompletionFinder COMP_POINT encoding translation and initialization.

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[maxnbk]

I only glanced over the code, but a local test of gitbash sourcing the completion .sh allowed me to autocomplete to a package name I have available, which explodes in a stacktrace on main, so I'll mark approved.