Slow installs or "pypi.ngc.nvidia.com" connection warnings

Installs crawl, or the log fills with repeated warnings like:

WARNING: Retrying (Retry(total=4, ...)) after connection broken by
'NameResolutionError("HTTPSConnection(host='pypi.ngc.nvidia.com', port=443):
Failed to resolve 'pypi.ngc.nvidia.com'")'

On most networks the install still finishes, it is just noisy and slow. On networks that silently drop unknown DNS instead of answering "no such host", pip can hang until it times out, which looks like a frozen or failed install.

Cause

NVIDIA retired their old package mirror pypi.ngc.nvidia.com. The hostname no longer exists.

If you installed StreamDiffusionTD before v0.3.0 (2025 or earlier), the old installer ran a helper package called nvidia-pyindex. That package wrote a pip config file pointing at the NVIDIA mirror. It was correct at the time and it worked fine for years.

Two things make this worth knowing:

1. That config is machine wide, not per install. It affects every pip install you run for any Python project, not just StreamDiffusionTD.
2. Updating StreamDiffusionTD does not remove it. Neither does a fresh install, a Full Update, or deleting the StreamDiffusion folder entirely. The file lives outside anything the installer manages, so it survives everything.

So you can be fully up to date on the newest version and still have this. StreamDiffusionTD stopped using nvidia-pyindex in v0.3.0, but it does not clean up the file the old version left behind.

Check whether you have it

python -m pip config debug

If any line mentions pypi.ngc.nvidia.com, you have it. The output also tells you which file it came from.

Fix

Open these two files, if they exist:

%APPDATA%\pip\pip.ini
%USERPROFILE%\pip\pip.ini

Delete any line referencing pypi.ngc.nvidia.com, including the extra-index-url and trusted-host entries that name it. A cleaned file looks like this:

[global]
index-url = https://pypi.org/simple

If the file has nothing left in it besides that, you can delete the file outright. Pip falls back to its defaults.

Make a copy first if you want to be careful. These are plain text files.

Also worth checking

While you are in there, look for this line:

no-cache-dir = true

That tells pip to never cache downloads, so every install re-downloads everything from scratch. It often ends up in the same file. Removing it makes repeat installs noticeably faster.

Verify

python -m pip config debug

No mention of pypi.ngc.nvidia.com means you are done.

Notes

• The newest installer detects this and warns you at the start of an install, but it will not edit your pip config for you. Changing machine wide settings from an installer can break unrelated Python work, so the fix is left to you.
• This is not caused by anything on your GPU, your drivers, or your TouchDesigner version.
• Recent installer versions no longer reference the dead mirror anywhere in their own code. Any remaining mention in your logs is coming from this config file.
• See also the Troubleshooting page.