Expected behavior It prints the beginning and end of the selection. Unexpected behavior It prints the beginning of the selection twice. Steps to reproduce the problem In fact, I do not know where the problem is located exactly, since I rely on 9fans.net/go/acme. Assuming it handles the API correctly, the steps are as follows: Create a file with the following content, build it and run on any selection: package main import ( "fmt" "os" "strconv" "9fans.net/go/acme" ) func main() { winid, _ := strconv.Atoi(os.Getenv("winid")) w, _ := acme.Open(winid, nil) w.ReadAddr() // make sure "addr" is open w.Ctl("addr=dot") r0, r1, _ := w.ReadAddr() fmt.Println(r0, r1) } (Error handling is omitted intentionally.) The address of the beginning is print twice, the end is lost. plan9port version a2567fcac9851e5cc965a236679f568b0e79cff2 OS version macOS 14.5 (23F79) ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T584db35e12efefbb-Mc9be6abf1986e4a93228d077 Delivery options: https://9fans.topicbox.com/groups/9fans/subscription