Problem pushing to Heroku with dm-migrations

I couldn't find anyone else having this error, so I hope it's not something specific to my machine or something.

-----> Heroku receiving push
-----> Sinatra app detected

-----> Installing gem data_mapper 1.0.0 from http://rubygems.org
      ERROR:  Error installing data_mapper:
       dm-migrations requires dm-core (~> 1.0.2, runtime)
!     Heroku push rejected, failed to install gem

error: hooks/pre-receive exited with error code 1
To git@heroku.com:episodes.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'git@heroku.com:episodes.git'

I'm using bundler 1.0.7 to manage my dependencies.

Here is my Gemfile:

source :rubygems
gem 'sinatra', '>= 1.0'
gem 'rake'
gem 'rspec', :require => 'spec'
gem 'data_mapper'
gem 'rack-test'
gem 'dm-core'
gem 'dm-sqlite-adapter'
gem 'dm-timestamps'
gem 'dm-validations'
gem 'dm-aggregates'
gem 'dm-migrations'
gem 'haml'

With Gemfile.lock (up-to-date)

GEM
  remote: http://rubygems.org/
  specs:
    addressable (2.2.3)
    data_mapper (1.0.2)
      dm-aggregates (= 1.0.2)
      dm-constraints (= 1.0.2)
      dm-core (= 1.0.2)
      dm-migrations (= 1.0.2)
      开发者_JAVA百科dm-serializer (= 1.0.2)
      dm-timestamps (= 1.0.2)
      dm-transactions (= 1.0.2)
      dm-types (= 1.0.2)
      dm-validations (= 1.0.2)
    data_objects (0.10.2)
      addressable (~> 2.1)
    diff-lcs (1.1.2)
    dm-aggregates (1.0.2)
      dm-core (~> 1.0.2)
    dm-constraints (1.0.2)
      dm-core (~> 1.0.2)
      dm-migrations (~> 1.0.2)
    dm-core (1.0.2)
      addressable (~> 2.2)
      extlib (~> 0.9.15)
    dm-do-adapter (1.0.2)
      data_objects (~> 0.10.2)
      dm-core (~> 1.0.2)
    dm-migrations (1.0.2)
      dm-core (~> 1.0.2)
    dm-serializer (1.0.2)
      dm-core (~> 1.0.2)
      fastercsv (~> 1.5.3)
      json_pure (~> 1.4)
    dm-sqlite-adapter (1.0.2)
      dm-do-adapter (~> 1.0.2)
      do_sqlite3 (~> 0.10.2)
    dm-timestamps (1.0.2)
      dm-core (~> 1.0.2)
    dm-transactions (1.0.2)
      dm-core (~> 1.0.2)
    dm-types (1.0.2)
      dm-core (~> 1.0.2)
      fastercsv (~> 1.5.3)
      json_pure (~> 1.4)
      stringex (~> 1.1.0)
      uuidtools (~> 2.1.1)
    dm-validations (1.0.2)
      dm-core (~> 1.0.2)
    do_sqlite3 (0.10.2)
      data_objects (= 0.10.2)
    do_sqlite3 (0.10.2-x86-mingw32)
      data_objects (= 0.10.2)
    extlib (0.9.15)
    fastercsv (1.5.4)
    haml (3.0.25)
    json_pure (1.4.6)
    rack (1.2.1)
    rack-test (0.5.7)
      rack (>= 1.0)
    rake (0.8.7)
    rspec (2.4.0)
      rspec-core (~> 2.4.0)
      rspec-expectations (~> 2.4.0)
      rspec-mocks (~> 2.4.0)
    rspec-core (2.4.0)
    rspec-expectations (2.4.0)
      diff-lcs (~> 1.1.2)
    rspec-mocks (2.4.0)
    sinatra (1.1.2)
      rack (~> 1.1)
      tilt (~> 1.2)
    stringex (1.1.0)
    tilt (1.2.2)
    uuidtools (2.1.1)

PLATFORMS
  ruby
  x86-mingw32

DEPENDENCIES
  data_mapper
  dm-aggregates
  dm-core
  dm-migrations
  dm-sqlite-adapter
  dm-timestamps
  dm-validations
  haml
  rack-test
  rake
  rspec
  sinatra (>= 1.0)

In my actual application, my requires are in this order:

require 'rubygems'
require 'bundler/setup'
require 'dm-core'
require 'dm-validations'
require 'dm-timestamps'
require 'dm-migrations'
require 'dm-types'
require 'haml'
require 'yaml'
require 'json'
require 'ostruct'
require 'sinatra'

Is there anything out of the ordinary that would have Heroku throw this error at me?

The problem is that you are using this repository: https://github.com/zapnap/sinatra-template

In addition to the Gemfile, it has a .gems file which specifies Datamapper 1.0.0. Get rid of that file and this should fix it.

I think, and I may be wrong, gem 'data_mapper' is like a meta gem. Remove that from list and try