Handle when Bundler is only available on the load path

3 files changed, 20 insertions, 7 deletions

diff --git a/lib/bundler/templates/Executable.bundler b/lib/bundler/templates/Executable.bundler
index 351eca7427..a9103ff6bd 100644
--- a/lib/bundler/templates/Executable.bundler
+++ b/lib/bundler/templates/Executable.bundler
@@ -57,11 +57,24 @@ m = Module.new do
   end
 
   def activate_bundler(bundler_version)
-    gem "bundler", bundler_version
-  rescue StandardError, LoadError => e
-    warn "Activating bundler (#{bundler_version}) failed:\n#{e.message}\n\nTo install the version of bundler this project requires, run `gem install bundler -v '#{bundler_version}'`"
+    gem_error = activation_error_handling do
+      gem "bundler", bundler_version
+    end
+    return if gem_error.nil?
+    require_error = activation_error_handling do
+      require "bundler/version"
+    end
+    return if require_error.nil? && Gem::Requirement.new(bundler_version).satisfied_by?(Gem::Version.new(Bundler::VERSION))
+    warn "Activating bundler (#{bundler_version}) failed:\n#{gem_error.message}\n\nTo install the version of bundler this project requires, run `gem install bundler -v '#{bundler_version}'`"
     exit 42
   end
+
+  def activation_error_handling
+    yield
+    nil
+  rescue StandardError, LoadError => e
+    e
+  end
 end
 
 m.load_bundler!
diff --git a/spec/install/binstubs_spec.rb b/spec/install/binstubs_spec.rb
index e5acc84e6a..9f361035e0 100644
--- a/spec/install/binstubs_spec.rb
+++ b/spec/install/binstubs_spec.rb
@@ -38,7 +38,7 @@ RSpec.describe "bundle install" do
     it "prints a deprecation notice" do
       bundle "config major_deprecations true"
       gembin("rackup")
-      expect(out).to include("Bundler is using a binstub that was created for a different gem.")
+      expect(out).to include("Bundler is using a binstub that was created for a different gem (rack).")
     end
 
     it "loads the correct spec's executable" do
diff --git a/spec/runtime/executable_spec.rb b/spec/runtime/executable_spec.rb
index 545fc97330..388ee049d0 100644
--- a/spec/runtime/executable_spec.rb
+++ b/spec/runtime/executable_spec.rb
@@ -78,7 +78,7 @@ RSpec.describe "Running bin/* commands" do
     expect(out).to eq("1.0")
   end
 
-  it "don't bundle da bundla" do
+  it "creates a bundle binstub" do
     build_gem "bundler", Bundler::VERSION, :to_system => true do |s|
       s.executables = "bundle"
     end
@@ -88,9 +88,9 @@ RSpec.describe "Running bin/* commands" do
       gem "bundler"
     G
 
-    bundle "binstubs bundler"
+    bundle! "binstubs bundler"
 
-    expect(bundled_app("bin/bundle")).not_to exist
+    expect(bundled_app("bin/bundle")).to exist
   end
 
   it "does not generate bin stubs if the option was not specified" do