Revert downgrading bundler mismatches to a warning

lib/rubygems.rb

@@ -268,10 +268,17 @@ def self.find_spec_for_exe(name, exec_name, requirements)
 
     return loaded if loaded && dep.matches_spec?(loaded)
 
-    spec = dep.spec_for_exe(exec_name)
+    specs = dep.matching_specs(true)
 
-    unless spec
+    specs = specs.find_all do |spec|
+      spec.executables.include? exec_name
+    end if exec_name
+
+    unless spec = specs.first
       msg = "can't find gem #{dep} with executable #{exec_name}"
+      if name == "bundler" && bundler_message = Gem::BundlerVersionFinder.missing_version_message
+        msg = bundler_message
+      end
       raise Gem::GemNotFoundException, msg
     end
 

lib/rubygems/bundler_version_finder.rb

@@ -41,11 +41,10 @@ def self.compatible?(spec)
     spec.version.segments.first == bundler_version.segments.first
   end
 
-  def self.prioritize!(specs)
-    match_index = specs.find_index { |spec| compatible?(spec) }
-    return unless match_index
+  def self.filter!(specs)
+    return unless bundler_version = self.bundler_version
 
-    specs.unshift(specs.delete_at(match_index))
+    specs.reject! { |spec| spec.version.segments.first != bundler_version.segments.first }
   end
 
   def self.bundle_update_bundler_version

lib/rubygems/dependency.rb

@@ -281,7 +281,7 @@ def matching_specs(platform_only = false)
       requirement.satisfied_by?(spec.version) && env_req.satisfied_by?(spec.version)
     end.map(&:to_spec)
 
-    Gem::BundlerVersionFinder.prioritize!(matches) if name == "bundler".freeze
+    Gem::BundlerVersionFinder.filter!(matches) if name == "bundler".freeze
 
     if platform_only
       matches.reject! do |spec|
@@ -325,36 +325,13 @@ def to_spec
     active = matches.find { |spec| spec.activated? }
     return active if active
 
-    unless prerelease?
-      # Move prereleases to the end of the list for >= 0 requirements
-      pre, matches = matches.partition { |spec| spec.version.prerelease? }
-      matches += pre if requirement == Gem::Requirement.default
-    end
-
-    select_first(matches)
-  end
-
-  def spec_for_exe(exec_name)
-    matches = matching_specs(true)
-
-    matches = matches.find_all do |spec|
-      spec.executables.include? exec_name
-    end if exec_name
+    return matches.first if prerelease?
 
-    select_first(matches)
-  end
-
-  private
-
-  def select_first(matches)
-    spec = matches.first
-    return unless spec
-
-    if !Gem::BundlerVersionFinder.compatible?(spec)
-      warn Gem::BundlerVersionFinder.missing_version_message
-    end
+    # Move prereleases to the end of the list for >= 0 requirements
+    pre, matches = matches.partition { |spec| spec.version.prerelease? }
+    matches += pre if requirement == Gem::Requirement.default
 
-    spec
+    matches.first
   end
 
 end

lib/rubygems/errors.rb

@@ -63,6 +63,9 @@ def initialize(name, requirement, specs)
     private
 
     def build_message
+      if name == "bundler" && message = Gem::BundlerVersionFinder.missing_version_message
+        return message
+      end
       names = specs.map(&:full_name)
       "Could not find '#{name}' (#{requirement}) - did find: [#{names.join ','}]\n"
     end

test/rubygems/test_gem.rb

@@ -321,14 +321,14 @@ def test_activate_bin_path_gives_proper_error_for_bundler
 
     File.open("Gemfile", "w") { |f| f.puts('source "https://rubygems.org"') }
 
-    _, err = capture_io do
+    e = assert_raises Gem::GemNotFoundException do
       load Gem.activate_bin_path("bundler", "bundle", ">= 0.a")
     end
 
-    assert_includes err, "Could not find 'bundler' (9999) required by your #{File.expand_path("Gemfile.lock")}."
-    assert_includes err, "To update to the latest version installed on your system, run `bundle update --bundler`."
-    assert_includes err, "To install the missing version, run `gem install bundler:9999`"
-    refute_includes err, "can't find gem bundler (>= 0.a) with executable bundle"
+    assert_includes e.message, "Could not find 'bundler' (9999) required by your #{File.expand_path("Gemfile.lock")}."
+    assert_includes e.message, "To update to the latest version installed on your system, run `bundle update --bundler`."
+    assert_includes e.message, "To install the missing version, run `gem install bundler:9999`"
+    refute_includes e.message, "can't find gem bundler (>= 0.a) with executable bundle"
   end
 
   def test_self_bin_path_no_exec_name

test/rubygems/test_gem_bundler_version_finder.rb

@@ -100,33 +100,33 @@ def test_compatible
     end
   end
 
-  def test_prioritize
+  def test_filter
     versions = %w[1 1.0 1.0.1.1 2 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1]
     specs = versions.map { |v| util_spec("bundler", v) }
 
-    assert_equal %w[1 1.0 1.0.1.1 2 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1], util_prioritize_specs(specs)
+    assert_equal %w[1 1.0 1.0.1.1 2 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1], util_filter_specs(specs).map(&:version).map(&:to_s)
 
     bvf.stub(:bundler_version, v("2.1.1.1")) do
-      assert_equal %w[2 1 1.0 1.0.1.1 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1], util_prioritize_specs(specs)
+      assert_equal %w[2 2.a 2.0 2.1.1], util_filter_specs(specs).map(&:version).map(&:to_s)
     end
     bvf.stub(:bundler_version, v("1.1.1.1")) do
-      assert_equal %w[1 1.0 1.0.1.1 2 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1], util_prioritize_specs(specs)
+      assert_equal %w[1 1.0 1.0.1.1], util_filter_specs(specs).map(&:version).map(&:to_s)
     end
     bvf.stub(:bundler_version, v("1")) do
-      assert_equal %w[1 1.0 1.0.1.1 2 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1], util_prioritize_specs(specs)
+      assert_equal %w[1 1.0 1.0.1.1], util_filter_specs(specs).map(&:version).map(&:to_s)
     end
     bvf.stub(:bundler_version, v("2.a")) do
-      assert_equal %w[2 1 1.0 1.0.1.1 2.a 2.0 2.1.1 3 3.a 3.0 3.1.1], util_prioritize_specs(specs)
+      assert_equal %w[2 2.a 2.0 2.1.1], util_filter_specs(specs).map(&:version).map(&:to_s)
     end
     bvf.stub(:bundler_version, v("3")) do
-      assert_equal %w[3 1 1.0 1.0.1.1 2 2.a 2.0 2.1.1 3.a 3.0 3.1.1], util_prioritize_specs(specs)
+      assert_equal %w[3 3.a 3.0 3.1.1], util_filter_specs(specs).map(&:version).map(&:to_s)
     end
   end
 
-  def util_prioritize_specs(specs)
+  def util_filter_specs(specs)
     specs = specs.dup
-    bvf.prioritize!(specs)
-    specs.map(&:version).map(&:to_s)
+    bvf.filter!(specs)
+    specs
   end
 
 end

test/rubygems/test_gem_dependency.rb

@@ -353,12 +353,16 @@ def test_to_specs_respects_bundler_version
 
     assert_equal [b, b_1], dep.to_specs
 
-    Gem::BundlerVersionFinder.stub(:bundler_version_with_reason, ["1.16", "reason"]) do
-      assert_equal [b_1, b], dep.to_specs
+    Gem::BundlerVersionFinder.stub(:bundler_version_with_reason, ["3.5", "reason"]) do
+      e = assert_raises Gem::MissingSpecVersionError do
+        dep.to_specs
+      end
+
+      assert_match "Could not find 'bundler' (3.5) required by reason.\nTo update to the latest version installed on your system, run `bundle update --bundler`.\nTo install the missing version, run `gem install bundler:3.5`\n", e.message
     end
 
     Gem::BundlerVersionFinder.stub(:bundler_version_with_reason, ["2.0.0.pre.1", "reason"]) do
-      assert_equal [b, b_1], dep.to_specs
+      assert_equal [b], dep.to_specs
     end
   end
 

test/rubygems/test_kernel.rb

@@ -104,10 +104,10 @@ def test_gem_bundler_missing_bundler_version
       quick_gem 'bundler', '1'
       quick_gem 'bundler', '2.a'
 
-      _, e = capture_io do
+      e = assert_raises Gem::MissingSpecVersionError do
         gem('bundler')
       end
-      assert_match "Could not find 'bundler' (55) required by reason.", e
+      assert_match "Could not find 'bundler' (55) required by reason.", e.message
     end
   end
 

test/rubygems/test_require.rb

@@ -399,10 +399,10 @@ def test_require_bundler_missing_bundler_version
       b2a = util_spec('bundler', '2.a', nil, "lib/bundler/setup.rb")
       install_specs b1, b2a
 
-      _, e = capture_io do
+      e = assert_raises Gem::MissingSpecVersionError do
         gem('bundler')
       end
-      assert_match "Could not find 'bundler' (55) required by reason.", e
+      assert_match "Could not find 'bundler' (55) required by reason.", e.message
     end
   end