Ensure we run installation Rake tasks in a clean env in TestEnv

If we call `system('rake', 'taks_name')`, `ENV['RUBYOPT']` is set to
`'-rbundler/setup'` but some tasks (e.g. `gitlab:gitaly:install` need
a clean env since they install their own Gem bundle.
Signed-off-by: Rémy Coutable <remy@rymai.me>

lib/tasks/gitlab/gitaly.rake

@@ -21,7 +21,7 @@ namespace :gitlab do
         create_gitaly_configuration
         # In CI we run scripts/gitaly-test-build instead of this command
         unless ENV['CI'].present?
-          Bundler.with_original_env { run_command!(%w[/usr/bin/env -u BUNDLE_GEMFILE] + [command]) }
+          Bundler.with_original_env { run_command!([command]) }
         end
       end
     end

spec/support/test_env.rb

@@ -63,6 +63,8 @@ module TestEnv
   # See gitlab.yml.example test section for paths
   #
   def init(opts = {})
+    Gitlab::Application.load_tasks
+
     # Disable mailer for spinach tests
     disable_mailer if opts[:mailer] == false
 
@@ -122,11 +124,13 @@ module TestEnv
   end
 
   def setup_gitlab_shell
-    shell_needs_update = component_needs_update?(Gitlab.config.gitlab_shell.path,
+    gitlab_shell_dir = File.dirname(Gitlab.config.gitlab_shell.path)
+    gitlab_shell_needs_update = component_needs_update?(gitlab_shell_dir,
       Gitlab::Shell.version_required)
 
-    unless !shell_needs_update || system('rake', 'gitlab:shell:install')
-      raise 'Can`t clone gitlab-shell'
+    unless !gitlab_shell_needs_update || Rake.application.invoke_task('gitlab:shell:install')
+      FileUtils.rm_rf(gitlab_shell_dir)
+      raise "Can't install gitlab-shell"
     end
   end
 
@@ -136,8 +140,9 @@ module TestEnv
     gitaly_needs_update = component_needs_update?(gitaly_dir,
       Gitlab::GitalyClient.expected_server_version)
 
-    unless !gitaly_needs_update || system('rake', "gitlab:gitaly:install[#{gitaly_dir}]")
-      raise "Can't clone gitaly"
+    unless !gitaly_needs_update || Rake.application.invoke_task("gitlab:gitaly:install[#{gitaly_dir}]")
+      FileUtils.rm_rf(gitaly_dir)
+      raise "Can't install gitaly"
     end
 
     start_gitaly(gitaly_dir)