Fix django admin (#2932)

Author: rhysyngsun

openedx/admin.py

@@ -20,6 +20,7 @@ class OpenEdxUserAdmin(ModelAdminRunActionsForAllMixin, admin.ModelAdmin):
     raw_id_fields = ["user"]
     actions = ["repair_all_faulty_openedx_users"]
     run_for_all_actions = ["repair_all_faulty_openedx_users"]
+    readonly_fields = ["has_sync_error", "sync_error_data"]
 
     def get_queryset(self, request):
         """Overrides base queryset"""

users/admin.py

@@ -48,12 +48,17 @@ def has_delete_permission(self, request, obj=None):  # noqa: ARG002
 
 
 _username_warning = """
-<div style="background-color: #dc3545; color: #fff; padding: 10px; font-size: 16px; border-radius: 5px;">
-   <strong>WARNING:</strong>
+<div style="background-color: #dc3545; color: #fff; padding: 10px; font-size: 16px; border-radius: 5px; margin-bottom: 10px;">
+   <strong>WARNING:</strong><br/>
    Changing this username will require you to apply the same change in edX immediately after.<br /><br>
    Do not make this change unless you can perform the same change to the edX username, or you have someone
    else lined up to do it.
 </div>
+<div style="background-color: #0088e2; color: #fff; padding: 10px; font-size: 16px; border-radius: 5px;">
+   <strong>NOTE:</strong><br/>
+   If the user has not been synced to openedx yet, you will need to set Desired Edx Username as well. <br/><br/>
+   This is ultimately the source of truth on what value to start with when attempting to create the user.
+</div>
 """
 
 
@@ -86,6 +91,7 @@ def pretty_sync_error_data(self, instance):
             {
                 "fields": (
                     "edx_username",
+                    "desired_edx_username",
                     "has_been_synced",
                     "has_sync_error",
                     "pretty_sync_error_data",