What does doCheck = true do exactly

[dpc]

Is it only about running unit-tests from the package tests?

When I look at logs of dependencies being building I see Checking somepackage 1.2.3 and Compiling somepackage 1.2.3 .

When I do cargo build locally I only ever get to see Compiling somepackage 1.2.3.

[ipetkov]

doCheck is understood by mkDerivation which decides if tests should be run or not (not all packages want to run their tests). Also when cross compiling nix will assume the value is set to false, but otherwise will honor whatever it is set to