Stop yarn workspaces focus ... creating symlinks to unrelated workspaces?

[protango]

I'm trying to use yarn to setup a minimal docker image for just one workspace in a larger monorepo. So far, yarn workspaces focus seems to be what I want, however it seems that it still creates symlinks in node_modules to all workspaces in the repo, not just the ones required by the "focussed" workspace. So I can't create the minimal environment I am looking for since unrelated code is still being pulled in. (My plan was to de-reference all the symlinks in node_modules then delete everything else except the app code and node_modules)

For example, consider the following dependency tree:

• Workspace_A
  • Depends on: Workspace_B
• Workspace_B
  • Depends on: External_Dependency_A
• Workspace_C
  • Depends on: External_Dependency_B

When I run yarn workspaces focus Workspace_A I would expect the following node_modules to be generated:

╠ Workspace_A (symlink)
╠ Workspace_B (symlink)
╠ External_Dependency_A

But instead I get the following:

╠ Workspace_A (symlink)
╠ Workspace_B (symlink)
╠ Workspace_C (symlink)
╠ External_Dependency_A

Note that the command has done it's job by ignoring External_Dependency_B since it's focused on Workspace_A, yet it still linked in Workspace_C despite the fact that it has nothing to do with Workspace_A. Is there any way to prevent this?