my vscode always rebuild mathlib

Stream: new members

[cybcat]

Hi everyone. I installed lean4 several days ago. When I first used it to prove theorems, vscode build mathlib for a long time. But when I use lean4 today my vscode rebuilt mathlib. How can I avoid this for it is too slow to build.
I tried lake exe cache get but this didn't make anything better.

[Kevin Buzzard]

lake exe cache get is the right answer, followed by lake build. If this doesn't work you'll need to give us more details.

[Shreyas Srinivas]

Close vscode (pkill everything vscode if required) run cache, let it finish, and then open the project.