Refreshing a mirror leads to errors for clients using that mirror

[dveeden]

Bug Report

The setup here is a single machine that has internet access and will function as a TiUP mirror to other machines.

1. What did you do?

On the mirror host do tiup mirror clone... etc to create a clone. Then every so often update the mirror.

Then on another host try to use the updated mirror.

2. What did you expect to see?

A functioning mirror allowing all machines in the network to install and update tiup components

3. What did you see instead?

Error: read manifest from mirror(http://ti-mirror.sqldb/compound/) failed: invalid signature for file timestamp.json: not enough signatures (0) for threshold 1 in timestamp.json

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

# tiup --version
1.10.2 tiup
Go Version: go1.18.3
Git Ref: v1.10.2
GitHash: 2de5b500c9fae6d418fa200ca150b8d5264d6b19

[AstroProfundis]

What exactly does Then every so often update the mirror. do?