SIGSEGV on tiup mirror renew with expired repo

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

I have my own custom tiup local repository.
Apparently, it expired and I wanted to renew a component.

tiup mirror set /Users/.../remote
tiup mirror renew alertmanager --days 365

2. What did you expect to see?

Successful component renew

3. What did you see instead?

tiup mirror renew alertmanager --days 365
read manifest from mirror(/Users/.../remote) failed: manifest timestamp.json has expired at: 2024-03-28T09:00:36+02:00
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x13d2e20]

goroutine 1 [running]:
github.com/pingcap/tiup/pkg/repository/v1manifest.(*Component).Base(0x49c7853411cd?)
        github.com/pingcap/tiup/pkg/repository/v1manifest/types.go:174
github.com/pingcap/tiup/pkg/repository/v1manifest.RenewManifest({0x182fe00, 0x0}, {0xc000241b98?, 0x1?, 0x1cd5720?}, {0xc000241b50, 0x1, 0x0?})
        github.com/pingcap/tiup/pkg/repository/v1manifest/manifest.go:420 +0x4c
github.com/pingcap/tiup/cmd.newMirrorRenewCmd.func1(0xc0002cb500?, {0xc0002ce5d0, 0x1, 0x172a6c7?})
        github.com/pingcap/tiup/cmd/mirror.go:371 +0x1b8
github.com/spf13/cobra.(*Command).execute(0xc0002cb500, {0xc0002ce570, 0x3, 0x3})
        github.com/spf13/cobra@v1.6.1/command.go:916 +0x87c
github.com/spf13/cobra.(*Command).ExecuteC(0xc0002c4000)
        github.com/spf13/cobra@v1.6.1/command.go:1044 +0x3a5
github.com/spf13/cobra.(*Command).Execute(...)
        github.com/spf13/cobra@v1.6.1/command.go:968
github.com/pingcap/tiup/cmd.Execute()
        github.com/pingcap/tiup/cmd/root.go:238 +0x46
main.main()
        github.com/pingcap/tiup/main.go:21 +0xf

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

tiup --version                           
1.15.0 v1.15.0-nightly-1
Go Version: go1.21.8
Git Ref: master
GitHash: 6f016925ab0d259bb07657f5ab83f2a2d7ef5656

Reproduce the failure with an expired local mirror using tiup mirror renew alertmanager --days 365. Read pkg/repository/v1manifest/types.go:174, pkg/repository/v1manifest/manifest.go:420, and cmd/mirror.go:371 to trace the nil component after manifest loading fails. Done means the command no longer panics and reports the expired manifest failure safely.