2026/06/15 21:46:11 Unsolicited response received on idle HTTP channel starting with "HTTP/1.1 400 Bad Request\r\nContent-Type: text/plain; charset=utf-8\r\nConnection: close\r\n\r\n400 Bad Request"; err=<nil>
--- FAIL: TestProxyListenerWithProxyClient (0.01s)
--- FAIL: TestProxyListenerWithProxyClient/test_skip_list (0.00s)
proxylistener_test.go:210: Start shutdown
proxylistener_test.go:236: Failed to get response: Post "http://[::]:42805/foo": readLoopPeekFailLocked: %!w(<nil>)
FAIL
ref: golang/go#31259 (comment)
ref: https://caddy.community/t/got-502-with-an-error-message-readlooppeekfaillocked-nil/13616/6