Webfetch on MacOs fails when connected via iPhone hotspot

Using CoPilot App v1.1.2 on MacOs 26.5.2 for some research (eg simplified to: 'Please summarise the last entry in the GitHub changelog') results in a webfetch of the URL, and if that fails, curl is used to fetch the same URL.
- If I connect via typical Wifi networks (home, work, cafe etc) that do not support IPv6, then the webfetch works and curl is never called.
- If I connect via iPhone hotspot (iOS 26.5.2) then the webfetch fails, but curl succeeds. Error message is that DNS resolves to a blocked address, and opening up the full error shows that DNS resolved to an IPv6 address.

I think what is happening is that the network is dual stacked (IPv4 and IPv6 addresses both returned by DNS) and the scenario above gives a synthetic IPv6 address. Webfetch should (and does) block use of the synthetic address, but fails to revert to the valid IPv4 address, which it should do.

I am fairly sure I saw this behaviour in the previous app version, but don't have a record of the version number.

首先，在通过 iPhone 热点连接时，于 macOS 上的 Copilot App v1.1.2 中重现 webfetch 失败，然后将其与典型的 Wi-Fi 网络和 curl fallback 进行比较。跟踪 DNS 返回被阻止的合成 IPv6 地址后 webfetch 的处理流程；完成的标准是它会重试或回退到有效的 IPv4 地址，而不是失败。

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