Fail gracefully when installing bundler fails

2 files changed, 20 insertions, 2 deletions

diff --git a/lib/bundler/postit_trampoline.rb b/lib/bundler/postit_trampoline.rb
index f648832202..7406612e5b 100644
--- a/lib/bundler/postit_trampoline.rb
+++ b/lib/bundler/postit_trampoline.rb
@@ -18,8 +18,16 @@ installed_version =
 installed_version &&= Gem::Version.new(installed_version)
 
 if !version.satisfied_by?(installed_version)
-  installer = BundlerVendoredPostIt::Installer.new(version)
-  installer.install!
+  begin
+    installer = BundlerVendoredPostIt::Installer.new(version)
+    installer.install!
+  rescue => e
+    abort <<-EOS.strip
+Installing the inferred bundler version (#{version}) failed.
+If you'd like to update to the current bundler version (#{installed_version}) in this project, run `bundle update --bundler`.
+The error was: #{e}
+    EOS
+  end
 
   Gem.loaded_specs.delete("bundler") unless defined?(Bundler)
   gem "bundler", version
diff --git a/spec/other/trampoline_spec.rb b/spec/other/trampoline_spec.rb
index 9a76819f8f..41a06c5125 100644
--- a/spec/other/trampoline_spec.rb
+++ b/spec/other/trampoline_spec.rb
@@ -69,6 +69,16 @@ describe "bundler version trampolining" do
       expect(out).to eq("Bundler version 1.12.3")
       expect(system_gem_path.join("gems", "bundler-1.12.3")).to exist
     end
+
+    it "fails gracefully when installing the bundler fails" do
+      ENV["BUNDLER_VERSION"] = "9999"
+      bundle "--version", :expect_err => true
+      expect(err).to eq(<<-E.strip)
+Installing the inferred bundler version (= 9999) failed.
+If you'd like to update to the current bundler version (1.12.5) in this project, run `bundle update --bundler`.
+The error was: Unable to resolve dependency: user requested 'bundler (= 9999)'
+      E
+    end
   end
 
   context "bundle update --bundler" do