When using both `--native-tls` or `UV_NATIVE_TLS=true` AND using `SSL_CERT_FILE=...`, which one should take preference?

[kdheepak]

Question

Currently SSL_CERT_FILE takes preference.

However, I'm running into a weird issue on one of my colleague's work computer where when SSL_CERT_FILE is specified uv sync runs into a proxy error (also same error when no environment variable is set).

However, when --native-tls or UV_NATIVE_TLS=true is set AND SSL_CERT_FILE is unset it works fine.

But when SSL_CERT_FILE is set AND --native-tls or UV_NATIVE_TLS=true is used, we still run into the same proxy error.

Intuitively, I would expect any environment variables which UV_ prefix to take precedence over a non prefixed environment variable, i.e. UV_NATIVE_TLS=true should take precedence over SSL_CERT_FILE.

Platform

Windows

Version

uv --version uv 0.6.14 (a4cec56 2025-04-09)