I’m trying to install a package from a private Azure DevOps registry using Yarn. I have configured my .yarnrc.yml file as follows:

npmScopes:
  mycompany:
    npmRegistryServer: https://pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/registry/
    npmAlwaysAuth: true
    npmAuthToken: <my-auth-token>

When I try to add the package with:

yarn add @mycompany/mypackage

I receive the following errors:

➤ YN0027: @mycompany/mypackage@unknown can't be resolved to a satisfying range
➤ YN0041: Invalid authentication (as an unknown user)
➤ Errors happened when preparing the environment required to run this command.

The setup works fine with npm using the following .npmrc configuration:

registry=https://pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/registry/
always-auth=true

; begin auth token
//pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/registry/:username=mycompany
//pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/registry/:_password=[ACCESS_TOKEN]
//pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/registry/:email=[EMAIL]
//pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/:username=mycompany
//pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/:_password=[ACCESS_TOKEN]
//pkgs.dev.azure.com/mycompany/_packaging/myproject/npm/:email=[EMAIL]
; end auth token

yarn version 3.6.4
npm version 10.8.1
node version 18.20.3

Verified the Package Name: I checked that the package @mycompany/mypackage exists in the registry.

Checked Authentication Token: Confirmed that the npmAuthToken is correct and has the necessary permissions.

Manual Configuration: Tried setting the registry and authentication token manually with the following commands: