Meaning of numbers when one builds mathlib

Stream: mathlib4

[Antoine Chambert-Loir]

When you build mathlib, either on your computer or on github, each file is attached with two numbers , such as in [1469/1791] Building Mathlib.LinearAlgebra.Pi
The second one is fixed in a given build, but changes from a build to another;
the first one increases at each file, but not necessarily by one.
What do these numbers mean exactly?

[Kevin Buzzard]

Files built so far v total files which need to be built in order to do the thing it's being asked to do

[Kevin Buzzard]

Different cores on your computer can compile different files at once so the numbers aren't in a nice pattern, things are starting and stopping all the time

[Antoine Chambert-Loir]

Thanks!

[Mario Carneiro]

also the second number goes up over time because when you build a file you can end up discovering more things that need to be built

[Antoine Chambert-Loir]

Oh, I see!

[Scott Morrison]

Typically that second number converges quite quickly to the final number.