Show more specific message for oauth errors

I forgot how hard it is to do view stuff in controllers.
I tried using the short lazy-lookup key '.oauth_error_html', which is supposed to work in controllers. But perhaps it doesn't work within a rescue?

app/controllers/admin/dfc_product_imports_controller.rb

@@ -35,10 +35,18 @@ module Admin
       end
 
       @count = imported.compact.count
+    rescue Rack::OAuth2::Client::Error => e
+      flash[:error] = I18n.t(
+        'admin.dfc_product_imports.index.oauth_error_html',
+        message: e.message,
+        oidc_settings_link: ActionController::Base.helpers.link_to(
+          I18n.t('spree.admin.tab.oidc_settings'), Rails.application.routes.url_helpers.admin_oidc_settings_path
+        )
+      ).html_safe
+      redirect_to admin_product_import_path
     rescue Faraday::Error,
            Addressable::URI::InvalidURIError,
-           ActionController::ParameterMissing,
-           Rack::OAuth2::Client::Error => e
+           ActionController::ParameterMissing => e
       flash[:error] = e.message
       redirect_to admin_product_import_path
     end

config/locales/en.yml

@@ -849,6 +849,7 @@ en:
       index:
         title: "Importing a DFC product catalog"
         imported_products: "Imported products:"
+        oauth_error_html: "Authentication error: %{message}. See %{oidc_settings_link}"
     enterprise_fees:
       index:
         title: "Enterprise Fees"

spec/system/admin/dfc_product_import_spec.rb

@@ -91,8 +91,11 @@ RSpec.describe "DFC Product Import" do
 
     click_button "Import"
 
-    expect(page).to have_content "invalid_grant"
-    expect(page).to have_content "session not active"
+    within ".flash" do
+      expect(page).to have_content "invalid_grant"
+      expect(page).to have_content "session not active"
+      expect(page).to have_link "OIDC Settings"
+    end
   end
 
   it "fails gracefully" do