Fix the broken spec for git fetcher

In other news, what is this spec? Why does it exist? How many kittens were
killed in the process of creating this spec?

Author: sethvargo

spec/fetchers/git_fetcher_spec.rb

@@ -76,22 +76,25 @@ def expect_git_ls_remote
 
         context 'when the ref does not exist' do
           let(:git_ls_remote_out) { '' }
+          let(:error_reporter) { double('ErrorReporter', explain: nil) }
+
+          before { Omnibus::Fetcher::ErrorReporter.stub(:new).and_return(error_reporter) }
 
           it 'should clone the Git repository and then fail while retrying 3 times' do
+            expect(error_reporter).to receive(:explain)
+              .with(%|Failed to fetch git repository 'git@example.com:test/project.git'|)
+
             4.times do
               expect_git_clone
-              4.times do
-                expect_git_ls_remote
-              end
             end
 
-            expect_any_instance_of(Omnibus::Fetcher::ErrorReporter).to receive(:explain)
-              .with(%q|Failed to find any commits for the ref '0.0.1'|)
+            expect_git_ls_remote
+
             expect(subject).to receive(:log).with(/git ls\-remote failed/).at_least(1).times
             expect(subject).to receive(:log).with(/git clone\/fetch failed/).at_least(1).times
             # Prevent sleeping to run the spec fast
             subject.stub(:sleep)
-            expect { subject.fetch }.to raise_error(/Could not parse SHA reference/)
+            expect { subject.fetch }.to raise_error(Omnibus::UnresolvableGitReference)
           end
         end
       end