From f9c6974d8b8be480db5daf4061a39731818c4bdb Mon Sep 17 00:00:00 2001
From: James Braza <jamesbraza@gmail.com>
Date: Thu, 2 Oct 2025 08:50:15 -0700
Subject: [PATCH] Warn when `UV_CACHE_DIR` has changed (#601)

Closes https://github.com/astral-sh/setup-uv/issues/592
---
 dist/save-cache/index.js | 13 +++++++++----
 src/save-cache.ts        | 16 ++++++++++++----
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/dist/save-cache/index.js b/dist/save-cache/index.js
index 552ac75..767e9a1 100644
--- a/dist/save-cache/index.js
+++ b/dist/save-cache/index.js
@@ -90056,12 +90056,17 @@ async function saveCache() {
     if (inputs_1.pruneCache) {
         await pruneCache();
     }
-    core.info(`Saving cache path: ${inputs_1.cacheLocalPath}`);
-    if (!fs.existsSync(inputs_1.cacheLocalPath) && !inputs_1.ignoreNothingToCache) {
-        throw new Error(`Cache path ${inputs_1.cacheLocalPath} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`);
+    let actualCachePath = inputs_1.cacheLocalPath;
+    if (process.env.UV_CACHE_DIR && process.env.UV_CACHE_DIR !== inputs_1.cacheLocalPath) {
+        core.warning(`The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${inputs_1.cacheLocalPath}".`);
+        actualCachePath = process.env.UV_CACHE_DIR;
+    }
+    core.info(`Saving cache path: ${actualCachePath}`);
+    if (!fs.existsSync(actualCachePath) && !inputs_1.ignoreNothingToCache) {
+        throw new Error(`Cache path ${actualCachePath} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`);
     }
     try {
-        await cache.saveCache([inputs_1.cacheLocalPath], cacheKey);
+        await cache.saveCache([actualCachePath], cacheKey);
         core.info(`cache saved with the key: ${cacheKey}`);
     }
     catch (e) {
diff --git a/src/save-cache.ts b/src/save-cache.ts
index caf0633..e79d657 100644
--- a/src/save-cache.ts
+++ b/src/save-cache.ts
@@ -52,14 +52,22 @@ async function saveCache(): Promise<void> {
     await pruneCache();
   }
 
-  core.info(`Saving cache path: ${cacheLocalPath}`);
-  if (!fs.existsSync(cacheLocalPath) && !ignoreNothingToCache) {
+  let actualCachePath = cacheLocalPath;
+  if (process.env.UV_CACHE_DIR && process.env.UV_CACHE_DIR !== cacheLocalPath) {
+    core.warning(
+      `The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${cacheLocalPath}".`,
+    );
+    actualCachePath = process.env.UV_CACHE_DIR;
+  }
+
+  core.info(`Saving cache path: ${actualCachePath}`);
+  if (!fs.existsSync(actualCachePath) && !ignoreNothingToCache) {
     throw new Error(
-      `Cache path ${cacheLocalPath} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`,
+      `Cache path ${actualCachePath} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`,
     );
   }
   try {
-    await cache.saveCache([cacheLocalPath], cacheKey);
+    await cache.saveCache([actualCachePath], cacheKey);
     core.info(`cache saved with the key: ${cacheKey}`);
   } catch (e) {
     if (