Add Bundler v4 opt-in to fix config deprecation warning (#137)

Author: mattbrictson

README.md

@@ -83,6 +83,14 @@ set :bundle_flags, '--quiet'                                    # this is defaul
 set :bundle_env_variables, {}                                   # this is default
 set :bundle_clean_options, ""                                   # this is default. Use "--dry-run" if you just want to know what gems would be deleted, without actually deleting them
 set :bundle_check_before_install, true                          # default: true. Set this to false to bypass running `bundle check` before executing `bundle install`
+set :bundle_version, 2                                          # default: 2. Set to 4 for Bundler 4 compatibility
+```
+
+If you are using Bundler 4 (which is the default in Ruby 4),
+make sure to set `:bundle_version` to avoid deprecation warnings:
+
+```ruby
+set :bundle_version, 4
 ```
 
 You can parallelize the installation of gems with bundler's jobs feature.

lib/capistrano/tasks/bundler.cap

@@ -16,13 +16,15 @@ namespace :bundler do
     on fetch(:bundle_servers) do
       within release_path do
         with fetch(:bundle_env_variables) do
+          config_args = fetch(:bundle_version, 2) >= 4 ? %w[config set] : %w[config]
+
           configuration = fetch(:bundle_config).dup || {}
           configuration[:gemfile] = fetch(:bundle_gemfile)
           configuration[:path] = fetch(:bundle_path)
           configuration[:without] = fetch(:bundle_without)
 
           configuration.each do |key, value|
-            execute :bundle, "config", "--local", key, value.to_s.shellescape unless value.nil?
+            execute :bundle, *config_args, "--local", key, value.to_s.shellescape unless value.nil?
           end
         end
       end
@@ -52,6 +54,8 @@ namespace :bundler do
           set :bundle_jobs, 4
           set :bundle_env_variables, {}
           set :bundle_clean_options, ""
+          set :bundle_check_before_install, true
+          set :bundle_version, 2
     DESC
   task install: :config do
     on fetch(:bundle_servers) do
@@ -124,5 +128,6 @@ namespace :load do
     set :bundle_env_variables, {}
     set :bundle_clean_options, ""
     set :bundle_check_before_install, true
+    set :bundle_version, 2
   end
 end