ci: also run upstream Nvim if_pyth tests

[brianhuster]

Nvim oldtest for if_pyth cover some cases not covered by test suite of pynvim. Instead of porting them to pynvim, we can just clone neovim repo to run those oldtest

[brianhuster]

Currently oldtest fail with the following error

Found errors in Test_python3_pyeval():
Caught exception in Test_python3_pyeval(): Vim(return):E5108: Lua: Vim:error caught while processing request 'python_eval ['vim']': Traceback (most recent call last):stack traceback:   [C]: at 0x5c4857697c46 @ command line..script /media/brianhuster/D/Projects/neovim/test/old/testdir/runtest.vim[657]..function RunTheTest[61]..Test_python3_pyeval[42]..provider#python3#Call, line 1

The test fail is

  let caught_859 = 0
  try
    let v = py3eval("vim")
  catch /can not serialize 'LegacyVim' object/
    let caught_859 = 1
  endtry
  call assert_equal(1, caught_859)

For pynvim installed with uv tool install pynvim --reinstall, if I run :let v = pyeval("vim"), it returns error can not serialize 'LegacyVim' object as the test expects. But if checkout to latest 0.6.0 release (git checkout 466ffc8cc0caacca91c434d0adb61dfba73ccd7e) and install from source with uv tool install . --reinstall, then run :let v = pyeval("vim") then the error is just

E5108: Lua: Vim:error caught while processing request 'python_eval ['vim']': Traceback (most recent call last):
stack traceback:
	[C]: at 0x58fda7d70460

No idea why it cannot show pynvim error now

[justinmk]

LegacyVim is stored in sys.modules here:

pynvim/pynvim/plugin/script_host.py

Lines 35 to 36 in 9f7df02

	self.legacy_vim = LegacyVim.from_nvim(nvim)
	sys.modules['vim'] = self.legacy_vim

perhaps the VimPathFinder.find_module which was removed in 9f7df02 was helping with serialization? Try reverting that commit here?

[justinmk]

if I install from uv registry, it works. But if I checkout to the same release (0.6.0) and install from current directory, it doesn't

We do some pre-processing for releases, e.g. we remove debug logging:

pynvim/scripts/disable_log_statements.sh

Lines 6 to 8 in 9f7df02

	for f in $(find . -name '*.py'); do
	echo "Processing: $f"
	../scripts/logging_statement_modifier.py "$f"

[brianhuster]

Oh yes, that is the reason. If I run ./scripts/disable_log_statements.sh before installing from source, then tests will pass

[brianhuster]

Ready for review. Only a few MacOS tests (that have always been flaky) fail

[justinmk]

yaml syntax https://github.com/neovim/pynvim/actions/runs/21753092793