EugenMayer/docker-sync · error

Unknown watch_strategy #{@options['watch_strategy']}

Error message

Unknown watch_strategy #{@options['watch_strategy']}

What it means

SyncProcess#set_watch_strategy raises on any options['watch_strategy'] outside 'fswatch', 'dummy', 'unison', 'remotelogs' (lib/docker-sync/sync_process.rb:69). Note the asymmetry with config-file handling: ProjectConfig#watch_strategy_for maps 'disable' to 'dummy' and falls back to defaults (project_config.rb:134-143), but SyncProcess does neither, so constructing it directly with 'disable' raises. Values are case-sensitive, untrimmed, and 'remotelogs' is one word (the class is WatchStrategy::Remote_logs).

Source

Thrown at lib/docker-sync/sync_process.rb:69

      when 'native_osx'
        @sync_strategy = DockerSync::SyncStrategy::NativeOsx.new(@sync_name, @options)
      else
        raise "Unknown sync_strategy #{@options['sync_strategy']}"
      end
    end

    def set_watch_strategy
      case @options['watch_strategy']
      when 'fswatch'
        @watch_strategy = DockerSync::WatchStrategy::Fswatch.new(@sync_name, @options)
      when 'dummy'
        @watch_strategy = DockerSync::WatchStrategy::Dummy.new(@sync_name, @options)
      when 'unison'
        @watch_strategy = DockerSync::WatchStrategy::Unison.new(@sync_name, @options)
      when 'remotelogs'
        @watch_strategy = DockerSync::WatchStrategy::Remote_logs.new(@sync_name, @options)
      else
        raise "Unknown watch_strategy #{@options['watch_strategy']}"
      end
    end

    def get_host_ip_default
      return '127.0.0.1' unless Dependencies::Docker::Driver.docker_toolbox?

      cmd = 'docker-machine ip $(docker-machine active)'
      stdout, stderr, exit_status = Open3.capture3(cmd)
      unless exit_status.success?
        raise "Error getting sync_host_ip automatically, exit code #{$?.exitstatus} ... #{stderr}"
      end
      stdout.gsub("\n",'')
    end

    def run
      @sync_strategy.run
      @watch_strategy.run
    end

View on GitHub (pinned to 4eab6de164)

Solutions

1. Use one of the four exact values: 'fswatch', 'dummy', 'unison', 'remotelogs', all lowercase.
2. Translate 'disable' to 'dummy' yourself when constructing SyncProcess directly.
3. Spell the log watcher 'remotelogs' (one word, no underscore).
4. Feed SyncProcess with options that came through ProjectConfig normalization rather than a raw hash.

Example fix

# before ('disable' is config-file syntax; SyncProcess wants 'dummy')
process = DockerSync::SyncProcess.new('appcode-sync',
  'src' => './src', 'watch_strategy' => 'disable')

# after
process = DockerSync::SyncProcess.new('appcode-sync',
  'src' => './src', 'watch_strategy' => 'dummy')

ALLOWED_WATCH = %w[fswatch dummy unison remotelogs].freeze
value = options['watch_strategy'] == 'disable' ? 'dummy' : options['watch_strategy']
abort "watch_strategy must be one of: #{ALLOWED_WATCH.join(', ')}" unless ALLOWED_WATCH.include?(value)
process = DockerSync::SyncProcess.new(name, options.merge('watch_strategy' => value))

WATCH_STRATEGIES = %w[fswatch dummy unison remotelogs].freeze

def watch_strategy?(value)
  value.is_a?(String) && WATCH_STRATEGIES.include?(value)
end

begin
  DockerSync::SyncProcess.new(name, options)
rescue RuntimeError => e
  raise unless e.message.start_with?('Unknown watch_strategy')
  abort "unsupported watch_strategy #{options['watch_strategy'].inspect}"
end

When it happens

Trigger: SyncProcess.new with 'watch_strategy' => 'disable' (fine inside docker-sync.yml, rejected when passed straight to SyncProcess), misspellings like 'remote_logs' or 'fswach', capitalized values like 'Dummy', or nil from a hand-built options hash.

Common situations: Reusing config-file vocabulary ('disable') in direct API code; misspelling remotelogs as remote_logs; options assembled from ENV or user input; docker-sync versions whose accepted watcher sets differ.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• Unknown sync_strategy #{@options['sync_strategy']}
• No docker-sync.yml configuration found in your path ( traver
• Your docker-sync.yml file does not include a version: "2"(Ad
• Your docker-sync.yml file does not match the required versio
• no syncs defined

AI-assisted analysis of EugenMayer/docker-sync@4eab6de164 (2026-08-23). Data as JSON: /api/errors/272845d9a29568ba. Report an issue: GitHub.