Gemfile

source 'http://rubygems.org'

gem 'sequel'
gem 'rspec'
gem 'sqlite3'

Gemfile.lock

GEM
  remote: http://rubygems.org/
  specs:
    diff-lcs (1.1.3)
    rspec (2.10.0)
      rspec-core (~> 2.10.0)
      rspec-expectations (~> 2.10.0)
      rspec-mocks (~> 2.10.0)
    rspec-core (2.10.1)
    rspec-expectations (2.10.0)
      diff-lcs (~> 1.1.3)
    rspec-mocks (2.10.1)
    sequel (3.36.1)
    sqlite3 (1.3.6)

PLATFORMS
  ruby

DEPENDENCIES
  rspec
  sequel
  sqlite3

sequel_stack_error.rb

require 'rubygems'
require 'sequel'
require 'rspec'

describe 'stack overflow spec' do
  before(:all) do
    DB = Sequel.sqlite
  end

  before(:each) do
    Sequel::Dataset.any_instance.stub(:import).and_raise('db error')
  end

  it 'raises db error' do
    expect { DB[:test].import([:a], [[1],[2],[3]]) }.to raise_error('db error')
  end
end