Active Support is not an runtime dependency of the gem

Author: rafaelfranca

lib/spring/binstub.rb

@@ -1,26 +1,6 @@
 command  = File.basename($0)
 bin_path = File.expand_path("../../../bin/spring", __FILE__)
 
-# When we run a command which does not go through Spring (e.g. DISABLE_SPRING
-# is used, or we just call 'rails' or something) then we get this warning from
-# Rubygems:
-#
-#   WARN: Unresolved specs during Gem::Specification.reset: activesupport (<= 5.1, >= 4.2)
-#   WARN: Clearing out unresolved specs.
-#   Please report a bug if this causes problems.
-#
-# This happens due to our dependency on activesupport, when Bundler.setup gets
-# called.  We don't actually *use* the dependency; it is purely there to
-# restrict the Rails version that we're compatible with.
-#
-# When the warning is shown, Rubygems just does the below.
-# Therefore, by doing it ourselves here, we can avoid the warning.
-if Gem::Specification.respond_to?(:unresolved_deps)
-  Gem::Specification.unresolved_deps.clear
-else
-  Gem.unresolved_deps.clear
-end
-
 if command == "spring"
   load bin_path
 else

spring.gemspec

@@ -13,11 +13,7 @@ Gem::Specification.new do |gem|
   gem.files         = Dir["LICENSE.txt", "README.md", "lib/**/*", "bin/*"]
   gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
 
-  # We don't directly use Active Support (Spring needs to be able to run
-  # without gem dependencies), but this will ensure that this version of
-  # Spring can't be installed alongside an incompatible Rails version.
-  gem.add_dependency 'activesupport', '>= 4.2'
-
   gem.add_development_dependency 'rake'
   gem.add_development_dependency 'bump'
+  gem.add_development_dependency 'activesupport'
 end