I built a monorepo using Lerna and Yarn workspaces.
Everything works fine but everytime I install a new dependency on a package (let's call him A) using:
yarn add <package_name>
Yarn adds it and then triggers the install script of all the packages in the monorepo, even the ones that A doesn't rely on.
It there anyway to avoid this? It takes a few moment to install them for no reason at all.
Try adding to the specific workspace with:-
yarn workspace <workspace_name> add <package_name>
For some docs check here
Using scope add the package to the particular module.
lerna add some_package_1 --scope=some_module_x
More: https://github.com/lerna/lerna/tree/master/commands/add#readme
You can try Yarn 2 with nodeLinker: node-modules in .yarnrc.yml. Yarn 2 guarantees to trigger rebuild only on packages that have their dependencies changed, this is something that was not guaranteed by Yarn 1. However there will still be a very rare case when seemingly unrelated packages be rebuilt if they are hoisted differently after adding new package, but this will happen very rarely.