ValueError: The "" URL scheme is not supported.

I get penguins.qmd from https://quarto.org/docs/dashboards/interactivity/shiny-python/index.html

I create a venv with the requirements:

uv venv -p 3.13.5
uv pip install shiny shinywidgets jupyter seaborn
source .venv/bin/activate

I can now see the app I expect in Firefox after using quarto preview penguins.qmd in bash.

I'd like to deploy it to Connect from the CLI. Because it has interactive content, I need to use rsconnect deploy rather than quarto deploy.

~/src/quarto-python-shiny via 🐍 v3.13.5 (quarto-python-shiny) via ⨁ v1.7.32 
[ 15:55:19 ] ❯ rsconnect deploy quarto penguins.qmd 
Inspecting Quarto project...                     [OK]
Inspecting Python environment...                     Warning: Python version constraint missing from pyproject.toml, setup.cfg or .python-version
             Connect will guess the version to use based on local environment.
             Consider specifying a Python version constraint.
[OK]
Traceback (most recent call last):
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/main.py", line 118, in wrapper
    result = func(*args, **kwargs)
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/click/decorators.py", line 34, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/main.py", line 1315, in deploy_quarto
    ce = RSConnectExecutor(
        ctx=ctx,
    ...<12 lines>...
        env_vars=env_vars,
    )
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/api.py", line 771, in __init__
    self.setup_client(cookies)
    ~~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/api.py", line 927, in setup_client
    self.client = RSConnectClient(self.remote_server, cookies)
                  ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/api.py", line 382, in __init__
    super().__init__(
    ~~~~~~~~~~~~~~~~^
        append_to_path(server.url, "__api__"),
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<2 lines>...
        cookies,
        ^^^^^^^^
    )
    ^
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/http_support.py", line 238, in __init__
    raise ValueError('The "%s" URL scheme is not supported.' % self._url.scheme)
ValueError: The "" URL scheme is not supported.
Internal error: The "" URL scheme is not supported.

From the log output, it isn't clear if I have done something wrong, or if this is an issue with rsconnect.

Note that I get the same error when I run sconnect deploy shiny . --entrypoint app.py

~/src/quarto-python-shiny via 🐍 v3.13.5 (quarto-python-shiny) via ⨁ v1.7.32 
[ 16:14:50 ] ❯ rsconnect deploy shiny . --entrypoint app.py
    Warning: Python version constraint missing from pyproject.toml, setup.cfg or .python-version
             Connect will guess the version to use based on local environment.
             Consider specifying a Python version constraint.
Traceback (most recent call last):
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/main.py", line 118, in wrapper
    result = func(*args, **kwargs)
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/click/decorators.py", line 34, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/main.py", line 1674, in deploy_app
    ce = RSConnectExecutor(
        ctx=ctx,
    ...<16 lines>...
        env_vars=env_vars,
    )
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/api.py", line 771, in __init__
    self.setup_client(cookies)
    ~~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/api.py", line 927, in setup_client
    self.client = RSConnectClient(self.remote_server, cookies)
                  ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/api.py", line 382, in __init__
    super().__init__(
    ~~~~~~~~~~~~~~~~^
        append_to_path(server.url, "__api__"),
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<2 lines>...
        cookies,
        ^^^^^^^^
    )
    ^
  File "/home/lsimpson/src/quarto-python-shiny/.venv/lib/python3.13/site-packages/rsconnect/http_support.py", line 238, in __init__
    raise ValueError('The "%s" URL scheme is not supported.' % self._url.scheme)
ValueError: The "" URL scheme is not supported.
Internal error: The "" URL scheme is not supported.

Tái hiện lỗi bằng các lệnh được hiển thị rsconnect deploy quarto và rsconnect deploy shiny. Bắt đầu trong rsconnect/api.py tại RSConnectExecutor.setup_client và RSConnectClient, sau đó kiểm tra rsconnect/http_support.py, nơi scheme của URL bị từ chối. Công việc được xem là hoàn tất khi bao gồm một bản sửa đã được xác minh hoặc chẩn đoán rõ ràng hơn cho URL máy chủ trống.