Merge #7594

7594: Fix flaky spec failure r=deivid-rodriguez a=deivid-rodriguez

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### What was the end-user or developer problem that led to this PR?

The problem was flaky tests: https://www.travis-ci.org/rubygems/bundler/jobs/639403049.

### What is your fix for the problem, implemented in this PR?

My diagnosis was that if our test code happens to run `Gem.configuration` before `ENV["HOME"]` is changed for our tests, this test starts failing because the test first writes to the global `~/.gemrc` file (not in `tmp/`), because `Gem.config_file` has that value memoized. Then, however, the `bundle install` subprocess infers `Gem.config_file` from the modified `ENV["HOME"]` and tries to read `tmp/home/.gemrc`. However, that file doesn't exist, so rubygems configuration is ignored and doesn't print an error like the test expects.
    
My fix is to make this test independent from the specific rubygems configuration in the main test process.

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Co-authored-by: David Rodríguez <deivid.rodriguez@riseup.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/spec/bundler/friendly_errors_spec.rb b/spec/bundler/friendly_errors_spec.rb
index e9189b0514..82553a3ca7 100644
--- a/spec/bundler/friendly_errors_spec.rb
+++ b/spec/bundler/friendly_errors_spec.rb
@@ -7,13 +7,13 @@ require "cgi"
 RSpec.describe Bundler, "friendly errors" do
   context "with invalid YAML in .gemrc" do
     before do
-      File.open(Gem.configuration.config_file_name, "w") do |f|
+      File.open(home(".gemrc"), "w") do |f|
         f.write "invalid: yaml: hah"
       end
     end
 
     after do
-      FileUtils.rm(Gem.configuration.config_file_name)
+      FileUtils.rm(home(".gemrc"))
     end
 
     it "reports a relevant friendly error message" do