Welcome Thread - v388

Report, as promised. spawnio 1.0.6, Windows 11, Python 3.12.13, TotalAV plus Defender both live, VS Code indexing the folder while it ran. Console code page 1252, which is the German Windows default.

The thing I actually asked about: it holds. Not two spots - four. project_generator.py:108,112 and custom_structure.py:456,460, all four ignore_errors=True. And the part I had not asked about is better than what I asked for:

except OSError as e:
    shutil.rmtree(project_path, ignore_errors=True)
    raise SpawnError(str(e)) from e
except BaseException:
    shutil.rmtree(project_path, ignore_errors=True)
    raise

from e keeps the chain, and except BaseException means Ctrl-C mid-generation also cleans up and still propagates. Most tools leave the half-built folder sitting there.

I did not want to take that from reading, so I forced it. Failed generation halfway with a marker exception, and at the same moment opened a handle on a file inside the half-created folder - a scanner, in effect. Counter-check first that the handle genuinely blocked deletion, otherwise the test proves nothing:

 with held handle
    exception         : RuntimeError
    text              : URSPRUNG-XYZZY-42
    original preserved: YES
    folder remnant    : yes
    handle did block  : YES

Original cause came through unchanged. A folder remnant is left, which is the right trade - better a leftover directory than a lost error message.

Now the one I did find, and it is not in the error path.

spawn create exits 1 on a fully successful run, on any Windows console that is not UTF-8, whenever stdout is not a terminal.

$ spawn create --name hallo-welt --template cli --cli-type utility --yes > out.txt 2> err.txt

EXIT: 1
UnicodeEncodeError: 'charmap' codec can't encode character '✨'

✨ is the sparkles in the success message. The project itself is fine - 682 files, git initialised, uv env built, uv.lock written. Everything worked. Then the line that says so killed the process.

spawn doctor does the same on \U0001f3e5, the hospital emoji in the report header.

The reason it is worth a fix rather than a shrug is the exit code. Anyone writing spawn create ... && cd my-project gets no cd. Any CI step wrapping it goes red on a green run. And because the failure lands after the work, the folder is there and correct, which makes it read like a tool that half-works rather than one that prints one character it cannot.

Confirmed cause and workaround in one line:

PYTHONIOENCODING=utf-8 spawn create ...   -> EXIT: 0, clean output
spawn create ...                          -> EXIT: 1, traceback

rich reports is_terminal: False, encoding: cp1252, legacy_windows: True here. When stdout is redirected, rich cannot do its Windows console handling and falls back to locale.getpreferredencoding(). Piped, redirected, captured by CI, or called from a wrapper - all the same case.

Worth separating: I counted 3155 characters cp1252 cannot encode across the package, but the large majority are inside template content written with encoding="utf-8", and those are correct as they are. It is only the console path that matters. utils/banner.py and the doctor report are where it bites.

If it is useful, the smallest fix is at the Console construction rather than at every call site - something like Console(file=open(sys.stdout.fileno(), "w", encoding="utf-8", errors="replace", closefd=False)), or sys.stdout.reconfigure(encoding="utf-8", errors="replace") at CLI entry. errors="replace" rather than a strict encode, so a missing glyph degrades to a ? instead of ending the run.

Two small ones from the Windows name tests.

spawn create --name PRN gives a raw traceback:

NotADirectoryError: [WinError 267] Der Verzeichnisname ist ungültig

Odd thing is CON and NUL are handled - they come out as SpawnError: A directory named 'CON' already exists. It does not exist, of course; Windows reserved device names make Path.exists() answer True, so the guard catches them by accident. Safe outcome, slightly wrong sentence. PRN apparently takes a different route and misses the guard entirely.

Everything else in that batch was clean, and this is the part I would not have predicted: spaces, a trailing dot, <, and ../escape all came back with Project name can only contain letters, numbers, hyphens... and no leftover directory in any case. An existing non-empty folder is refused, and the file I planted in it was untouched afterwards. That is the check most scaffolders get wrong.

Not your bug: I tried a 287-character working directory. Windows itself refuses to start a process there -CreateProcess fails before spawn gets a single byte. Nothing you can do about that from inside Python, and I would not count it.

One friction note, not a bug: this machine had Python 3.10 and 3.11, both still supported, and pip install spawnio finds nothing on either. uv python install 3.12 fixed it in eight seconds, and uv is a prerequisite anyway - but the README's "Prerequisites" is where I would say the 3.12 out loud, since the pip error is a wall of red for someone who has not read it.

So: one real fix, two cosmetic, and the error path you were asked about survives a machine with a virus scanner holding files open.

Worth saying plainly, because it is the unusual part. Every failure I could manufacture was handled, and the only thing that actually broke was printing a sparkle. That is backwards from most tools I have poked at, where the happy path is polished and the failure paths are where the bodies are buried. Yours is the other way round, and the other way round is the harder one to build - nobody sees it, nobody thanks you for it, and it is the only part that matters on someone else's machine at 2am.

The except BaseException is the line I keep coming back to. except Exception would have looked identical in review, passed every test, and left a half-built folder behind on every Ctrl-C. Someone chose the wider one on purpose.

And it went both ways: after writing this up I went and looked at our own generators, and two of them clean up after nothing at all. So thanks for the code review in the other direction - I did not expect to come out of testing someone else's tool with a bug list for my own.

Haven't really tried it , I've been committed to Claude since the beginning and I'm used to how it works by now and i don't want to lose the memory and sessions structure and the work flow i have since i'm in the middle of restructuring the app base . The app i'm working on is a bit huge and will need another year to finish (an app for personal use ) so honestly i don't want to risk it cus i tried other models before and they broke the app (luckily i tried it on a copy , not the original ) . So maybe once i'm done with this app , i'll try other options at that time. I heard alot of good things about Deepseek V4 though they increased the prices . Who knows when i'm done with this app what kind of models will be available.