From 74106dfb47332d8b1c653c8b550410a5c017a472 Mon Sep 17 00:00:00 2001
From: David Hotham <david.hotham@blueyonder.co.uk>
Date: Sat, 25 Jun 2022 14:54:28 +0100
Subject: [PATCH] assert repository not added to pool twice

---
 src/poetry/repositories/pool.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/poetry/repositories/pool.py b/src/poetry/repositories/pool.py
index 0e68cc6997b..49f0c18adb7 100644
--- a/src/poetry/repositories/pool.py
+++ b/src/poetry/repositories/pool.py
@@ -62,6 +62,8 @@ def add_repository(
         Adds a repository to the pool.
         """
         repository_name = repository.name.lower()
+        if repository_name in self._lookup:
+            raise RuntimeError(f"{repository_name} already in pool")
 
         if default:
             if self.has_default():