In my monorepo, I have 3 packages package1, package2, package3, each package contains a npm script named build.
However, these packages are not linked together. I.e. there are no require() in any of those packages linking to a sibling package.
From the root folder, I run lerna run build. It seems to run build of the packages in the alphabetically order.
Is there a way to specify the order to run the build commands of these packages?
--sort won't work because they are not linked.
You don't specify the order, you specify the topology by including a package as a dependency of another.
If package1 needs to be built before package2 you add package1 to the dependencies of package2 in the latter's package.json file. If you do not want package2 to directly depend on package1 (e.g. on production) you can still add it into devDependencies and Lerna will understand the dependency.
From lerna -h:
--sort Sort packages topologically (dependencies before dependents). Pass --no-sort to disable. [boolean] [default: true]
Note Some commands can be ran ignoring this topology, for example from lerna exec's --parallel option documentation:
completely disregards concurrency and topological sorting