What causes "Please specify a CLASS (model)" in alexreisner/geocoder?

Run the task with the CLASS env var set to your model name: `rake geocoder:all CLASS=Venue`.

alexreisner/geocoder · error · RuntimeError

Please specify a CLASS (model)

Error message

Please specify a CLASS (model)

What it means

The geocoder:all rake task batch-geocodes records of a model, and reads the model class name from the CLASS environment variable. If CLASS (or class) is not set, it raises immediately because it has no model to geocode.

Solutions

Run the task with the CLASS env var set to your model name: `rake geocoder:all CLASS=Venue`.
Optionally add SLEEP, BATCH, LIMIT, REVERSE env vars as needed (e.g. CLASS=Venue BATCH=500).
Check spelling/casing: the task accepts CLASS or class, nothing else.
If invoking programmatically, pass ENV['CLASS'] before calling the rake task.

Example fix

// before
bundle exec rake geocoder:all
// after
CLASS=Venue bundle exec rake geocoder:all

Defensive patterns

Strategy: validation

Validate before calling

# shell check before invoking the task
[ -n "$CLASS" ] || { echo "Usage: rake geocoder:all CLASS=MyModel"; exit 1; }
rake geocoder:all CLASS="$CLASS"

Try / catch

begin
  Rake::Task['geocoder:all'].invoke
rescue RuntimeError => e
  raise unless e.message == 'Please specify a CLASS (model)'
  warn 'Set the CLASS env var, e.g. rake geocoder:all CLASS=Venue'
end

Prevention

Always invoke the task as `rake geocoder:all CLASS=YourModel`; never rely on a default.
Wrap the invocation in a script/Makefile target that validates CLASS is set first.
Remember only CLASS or class (either case of this exact word) is read; MODEL or other names are ignored.
In CI, export CLASS explicitly or fail fast with a usage message.

When it happens

Trigger: Running `rake geocoder:all` (or `bundle exec rake geocoder:all`) without CLASS=..., or misspelling the env var (e.g. `class=Venue` lowercase works, but `MODEL=Venue` does not), or setting it in the wrong shell/environment so it is empty.

Common situations: Developers migrating from other gems' rake tasks that use a different env var name; running the task from CI or a Procfile where env vars were not forwarded; forgetting the argument after copying the task name from docs.

Understand the failure class

Background: "--flag is required" and "must specify" CLI errors: how missing-required-flag validation works and how to fix it — this error's family across 20 libraries.

Related errors

AI-assisted analysis of alexreisner/geocoder@c10bd70121 (2026-09-15). Data as JSON: /api/errors/f71abf7e8c200a19. Report an issue: GitHub.

Appendix: source

Thrown at lib/tasks/geocoder.rake:11

require "geocoder/models/mongoid"

namespace :geocode do
  desc "Geocode all objects without coordinates."
  task :all => :environment do
    class_name = ENV['CLASS'] || ENV['class']
    sleep_timer = ENV['SLEEP'] || ENV['sleep']
    batch = ENV['BATCH'] || ENV['batch']
    reverse = ENV['REVERSE'] || ENV['reverse']
    limit = ENV['LIMIT'] || ENV['limit']
    raise "Please specify a CLASS (model)" unless class_name
    klass = class_from_string(class_name)
    batch = (batch.to_i unless batch.nil?) || 1000
    orm = (klass < Geocoder::Model::Mongoid) ? 'mongoid' : 'active_record'
    reverse = false unless reverse.to_s.downcase == 'true'

    geocode_record = lambda { |obj|
      reverse ? obj.reverse_geocode : obj.geocode
      obj.save
      sleep(sleep_timer.to_f) unless sleep_timer.nil?
    }

    scope = reverse ? klass.not_reverse_geocoded : klass.not_geocoded
    scope = scope.limit(limit) if limit
    if orm == 'mongoid'
      scope.each do |obj|
        geocode_record.call(obj)
      end
    elsif orm == 'active_record'

View on GitHub (pinned to c10bd70121)