Only attempt a config migration once per launch

src/platform/linux/misc.cpp

@@ -106,12 +106,16 @@ namespace platf {
    */
   fs::path
   appdata() {
+    static std::once_flag migration_flag;
+    static fs::path config_path;
+
+    // Ensure migration is only attempted once
+    std::call_once(migration_flag, []() {
       bool found = false;
       bool migrate_config = true;
       const char *dir;
       const char *homedir;
       const char *migrate_envvar;
-    fs::path config_path;
 
       // Get the home directory
       if ((homedir = getenv("HOME")) == nullptr || strlen(homedir) == 0) {
@@ -147,7 +151,7 @@ namespace platf {
             fs::rename(old_config_path, config_path, ec);
             if (ec) {
               std::cerr << "Migration failed: " << ec.message() << std::endl;
-            return old_config_path;
+              config_path = old_config_path;
             }
           }
           else {
@@ -157,6 +161,7 @@ namespace platf {
           }
         }
       }
+    });
 
     return config_path;
   }