fix: handle empty YAML config files gracefully

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## {{ UNRELEASED_VERSION }} - [{{ UNRELEASED_DATE }}]({{ UNRELEASED_LINK }})
 
+* Fixed crash when `config.yml` is empty instead of containing `{}` [#439](https://github.com/lando/core/issues/439)
+
 ## v3.26.2 - [December 17, 2025](https://github.com/lando/core/releases/tag/v3.26.2)
 
 * Updated to use new Lando Alliance Apple Developer certificates

lib/cli.js

@@ -558,7 +558,7 @@ module.exports = class Cli {
     const Yaml = require(`../lib/yaml`);
     const yaml = new Yaml();
     const configFile = path.join(this.defaultConfig().userConfRoot, 'config.yml');
-    const config = (fs.existsSync(configFile)) ? yaml.load(configFile) : {};
+    const config = (fs.existsSync(configFile)) ? yaml.load(configFile) || {} : {};
     const file = yaml.dump(configFile, _.assign({}, config, data));
     return yaml.load(file);
   }

lib/lando.js

@@ -465,7 +465,7 @@ module.exports = class Lando {
     }
 
     // Load the config and augment so we can get an App
-    const config = lmerge({}, ..._.map(landoFiles, file => yaml.load(file)));
+    const config = lmerge({}, ..._.map(landoFiles, file => yaml.load(file) || {}));
     this.log.info('loading app %s from config files', config.name, landoFiles);
     // Return us some app!
     const App = require('./app');

utils/load-config-files.js

@@ -52,7 +52,7 @@ module.exports = files => _(files)
   .filter(source => fs.existsSync(source) || fs.existsSync(source.file))
   // If the file is just a string lets map it to an object
   .map(source => {
-    return _.isString(source) ? {file: source, data: yaml.load(fs.readFileSync(source))} : source;
+    return _.isString(source) ? {file: source, data: yaml.load(fs.readFileSync(source)) || {}} : source;
   })
   // Add on the root directory for mapping purposes
   .map(source => _.merge({}, source, {root: path.dirname(source.file)}))