A friend once tried to update Arch Linux on a wifi behind a captive portal. Pacman broke because instead of a package list it downloaded the captive portal logi

A friend once tried to update Arch Linux on a wifi behind a captive portal. Pacman broke because instead of a package list it downloaded the captive portal login page and failed to parse it, leading to mystery hunt for my friend troubleshooting the issue. With an HTTPS mirror it would have just failed to connect or handshake with the mirror.