fix: include runner image in cache key to prevent cross-provider collisions

README.md

@@ -68,7 +68,7 @@ When using `cache_key`, you can use template variables to reference internal val
 Available template variables:
 - `{{version}}` - The mise version (from the `version` input)
 - `{{cache_key_prefix}}` - The cache key prefix (from `cache_key_prefix` input or default)
-- `{{platform}}` - The target platform (e.g., "linux-x64", "macos-arm64")
+- `{{platform}}` - The target platform, including the runner image (e.g., "linux-x64-ubuntu24", "macos-arm64-macos15", "linux-x64-self-hosted"). The trailing segment is `process.env.ImageOS` on github-hosted runners and falls back to `"self-hosted"` elsewhere — preventing cache collisions when the same repo runs on different runner providers (github-hosted, namespace.so, self-hosted).
 - `{{file_hash}}` - Hash of all mise configuration files
 - `{{mise_env}}` - The MISE_ENV environment variable value
 - `{{install_args_hash}}` - SHA256 hash of the sorted tools from install args

src/index.ts

@@ -483,11 +483,7 @@ async function saveCache(cacheKey: string): Promise<void> {
 }
 
 async function getTarget(): Promise<string> {
-  let { arch } = process
-
-  // quick overwrite to abide by release format
-  if (arch === 'arm') arch = 'armv7' as NodeJS.Architecture
-
+  const arch = process.arch === 'arm' ? 'armv7' : process.arch
   switch (process.platform) {
     case 'darwin':
       return `macos-${arch}`
@@ -500,13 +496,25 @@ async function getTarget(): Promise<string> {
   }
 }
 
+/**
+ * Identifies the runner image so cached binaries from one provider
+ * (github-hosted, namespace.so, BuildJet, self-hosted) aren't restored
+ * onto another provider's image where their compiled-in paths and libc
+ * versions don't match. GitHub-hosted images export `ImageOS`
+ * (e.g. "macos15", "ubuntu24"); other runners leave it unset and pool
+ * under "self-hosted".
+ */
+function getRunnerImageId(): string {
+  return process.env.ImageOS || 'self-hosted'
+}
+
 async function processCacheKeyTemplate(template: string): Promise<string> {
   // Get all available variables
   const version = core.getInput('version')
   const installArgs = core.getInput('install_args')
   const cacheKeyPrefix = core.getInput('cache_key_prefix') || 'mise-v1'
   const miseEnv = process.env.MISE_ENV?.replace(/,/g, '-')
-  const platform = await getTarget()
+  const platform = `${await getTarget()}-${getRunnerImageId()}`
 
   // Calculate file hash
   const fileHash = await glob.hashFiles(MISE_CONFIG_FILE_PATTERNS.join('\n'))