Didn't find a direct solution to that; opened an issue about what I think is a related problem with shared vaults on Windows (https://github.com/dendronhq/dendron/issues/1050). I ended with the following workaround:

text
.
├── workspace-1
│   ├── personal-vault-A
│   └── shared-vault-A
├── workspace-2
│   ├── personal-vault-B
│   └── shared-vault-B

yml
// workspace-1
vaults:
    - fsPath: personal-vault-A
    - fsPath: shared-vault-A
    - fsPath: shared-vault-B
      workspace: workspace-2
      remote:
         url: git@github.com:workspace-2

yml
// workspace-2
vaults:
    - fsPath: personal-vault-B
    - fsPath: shared-vault-B
    - fsPath: shared-vault-A
      workspace: workspace-1
      remote:
         url: git@github.com:workspace-1

Which basically makes

workspace-1

pull

shared-vault-B

from

workspace-2

and vice versa. You end with two copies of shared vaults though. It works, but a bit finicky because you need to sync the workspaces often otherwise the shared vaults get out of sync. You don't get the error though. Also need to add

workspace-1/2

to corresponding

.gitignore

files, so you don't end up syncing full workspaces into each other.