对我来说，问题出在下面：

Well, for me, the issue has been what you see below:

user@PC:~$ ls -al ~/.android/
total 20
drwxrwxr-x  3 user    user 4096 Jun  7 15:46 .
drwxr-xr-x 30 user    user 4096 Sep 19 11:30 ..
-rw-------  1 root    root 1704 Jun  7 15:46 adbkey
-rw-r--r--  1 root    root  710 Jun  7 15:46 adbkey.pub
drwxrwxr-x  2 user    user 4096 Jun  7 15:42 cache

注意我的 adbkey 和匹配的公钥是如何由root拥有的？
我第一次在此计算机上运行 adb任何内容是root用户。
修复很容易，您可能已经知道： sudo chown user：user〜/ .android / adbkey *

Notice how my adbkey and the matching public key are owned by root? The first time I've ran adb anything on this machine has been as root. The fix is easy and you probably already know it: sudo chown user:user ~/.android/adbkey*