Why `tiup -v` need mirror be set?

[wuhuizuo]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

without any mirror setting, I run tiup -v

2. What did you expect to see?

exit with 0 and output the version detail.

3. What did you see instead?

error happened:

Please check for root manifest file, you may download one from the repository mirror, or try `tiup mirror set` to force reset it.
Error: initial repository from mirror(https://tiup-mirrors.pingcap.com/) failed: error loading manifest root.json: open /root/.tiup/bin/root.json: no such file or directory

4. What version of TiUP are you using (tiup --version)?

1.14.0 tiup
Go Version: go1.21.5
Git Ref: v1.14.1
GitHash: 23f7b0f0f3a0ad29e90a7b12b1097e8d4074cb3e