vfox backend doesn't honor url_replacements settings

[markussiebert]

Description

The vfox backend doesn't respect the [settings.url_replacements] configuration when downloading tools. Other backends like aqua properly apply URL replacements, but vfox uses its own HTTP client that bypasses mise's URL replacement mechanism.

Example

With this configuration in ~/.config/mise/config.toml:

toml
[settings.url_replacements]
"https://download.redis.io/releases/" = "https://my-proxy.com/"

When installing redis (which uses vfox backend):

bash
MISE_VERBOSE=1 mise install redis@latest

The output shows:

INFO Downloading https://download.redis.io/releases/redis-8.6.1.tar.gz

Expected: Should download from https://my-proxy.com/redis-8.6.1.tar.gz

Root Cause

The vfox crate (crates/vfox/src/vfox.rs line 235) uses its own reqwest client:

async fn download(&self, url: &Url, sdk: &Plugin, version: &str) -> Result<PathBuf> {
   // ...
   let resp = CLIENT.get(url.clone()).send().await?;  // Uses vfox's CLIENT

This CLIENT is defined in crates/vfox/src/http.rs and doesn't apply mise's URL replacements defined in src/http.rs::apply_url_replacements().

In contrast, the aqua backend uses mise's HTTP client (HTTP.download_file()) which properly applies URL replacements.

Suggested Fix

Pass URL replacements to the vfox crate and apply them before making requests. This could be done by:

1. Adding url_replacements field to the Vfox struct
2. Applying replacements in the download() method before the HTTP request
3. Passing settings from mise when creating the vfox instance

Workaround

Currently, the only workaround is to use a different backend (like aqua) for tools that need URL replacements, or configure URL replacements at the network/proxy level.

Environment

• mise version: 2026.3.0
• OS: macOS (but affects all platforms)