hashicorp/vagrant · error · Vagrant::Errors::VagrantfileSyntaxError

There is a syntax error in the following Vagrantfile. The sy

Error message

There is a syntax error in the following Vagrantfile. The syntax error message is reproduced below for convenience:

%{file}

What it means

Raised as Vagrant::Errors::VagrantfileSyntaxError from Config::Loader#procs_for_path (lib/vagrant/config/loader.rb:290) when Kernel.load(path) on the Vagrantfile raises SyntaxError — the file is not parseable Ruby. The raw Ruby parser message (which includes the file, line, and offending token) is passed through verbatim in the `file` placeholder, so users see Ruby's own diagnostic.

Source

Thrown at lib/vagrant/config/loader.rb:290

        else
          raise ArgumentError, "Unknown configuration source: #{reliably_inspected_sources[source]}"
        end
      end

      # This returns an array of `Proc` objects for the given path source.
      #
      # @param [String] path Path to the file which contains the proper
      #   `Vagrant.configure` calls.
      # @return [Array<Proc>]
      def procs_for_path(path)
        @logger.debug("Load procs for pathname: #{path}")

        return Config.capture_configures do
          begin
            Kernel.load path
          rescue SyntaxError => e
            # Report syntax errors in a nice way.
            raise Errors::VagrantfileSyntaxError, file: e.message
          rescue SystemExit
            # Continue raising that exception...
            raise
          rescue Vagrant::Errors::VagrantError
            # Continue raising known Vagrant errors since they already
            # contain well worded error messages and context.
            raise
          rescue Exception => e
            @logger.error("Vagrantfile load error: #{e.message}")
            @logger.error(e.backtrace.join("\n"))

            line = "(unknown)"
            if e.backtrace && e.backtrace[0]
              e.backtrace[0].split(":").each do |part|
                if part =~ /\d+/
                  line = part.to_i
                  break
                end

View on GitHub (pinned to 35f3160f4a)

Solutions

  1. Run `ruby -c Vagrantfile` to get the exact parser error and line number
  2. Fix the reported line — usually a missing or extra `end`, `do`, quote, or comma
  3. If the file is generated, fix the template/generator and regenerate rather than hand-patching
  4. Re-run `vagrant validate` to confirm the file parses before running real commands

Example fix

# before
Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/jammy64"
# missing `end` for the configure block

# after
Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/jammy64"
end
Defensive patterns

Strategy: validation

Validate before calling

# Parse-check before any vagrant automation
out = `ruby -c Vagrantfile 2>&1`
abort "Vagrantfile syntax error:\n#{out}" unless $?.success? && out.include?("Syntax OK")

Try / catch

begin
  Vagrant::Environment.new(cwd: dir).vagrantfile
rescue Vagrant::Errors::VagrantfileSyntaxError => e
  abort "Fix Vagrantfile syntax: #{e.extra_data[:file]}"
end

Prevention

When it happens

Trigger: Any vagrant command in a project whose Vagrantfile (or the file being loaded as it) fails to parse: unbalanced end/do, unmatched quote, stray character, malformed heredoc, or a missing `do` keyword. The exception happens during Kernel.load before any config block is captured or evaluated.

Common situations: Hand-editing a Vagrantfile and dropping an `end`; git merges that break block structure; template/ERB generators emitting invalid Ruby; Windows line endings or smart quotes pasted from blog posts.

Related errors

AI-assisted analysis of hashicorp/vagrant@35f3160f4a (2026-08-21). Data as JSON: /api/errors/aa84175dbcf1d1a0. Report an issue: GitHub.