not null;
Jobsets alter column nixExprPath drop not null;
Jobsets add column type integer default 0;
Jobsets add column flake text;
Jobsets add check ((type = 0) = (nixExprInput is not null and nixExprPath is not null));
Jobsets add check ((type = 1) = (flake is not null));
JobsetEvals add column flake text;
Jobsets alter column nixExprInput drop