Load vendored persistent before activating Artifice in-process

Artifice replaces Gem::Net::HTTP, so when bundler/vendored_persistent
gets lazily required while Artifice is active, the vendored Persistent
classes are defined under the Artifice replacement. After deactivation
Gem::Net::HTTP::Persistent becomes unresolvable, and the vendored
connection_pool fork hook then raises NameError on any later
Process.fork in the same rspec worker, failing worker_spec whenever it
shares a process with parallel_installer_spec. Load it up front like
gem_remote_fetcher_spec already does, before requiring
support/artifice/compact_index, which activates Artifice on load.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: hsbt

spec/bundler/installer/parallel_installer_spec.rb

@@ -8,6 +8,11 @@
 RSpec.describe Bundler::ParallelInstaller do
   describe "priority queue" do
     before do
+      # Anchor the vendored Persistent classes on the real Gem::Net::HTTP
+      # before Artifice replaces it, see Artifice.activate_with. Requiring
+      # support/artifice/compact_index already activates Artifice, so this
+      # must come first.
+      require "bundler/vendored_persistent"
       require "support/artifice/compact_index"
       Artifice.activate_with(CompactIndexAPI)
 
@@ -98,6 +103,11 @@
         skip "This example does not work under a parent make jobserver"
       end
 
+      # Anchor the vendored Persistent classes on the real Gem::Net::HTTP
+      # before Artifice replaces it, see Artifice.activate_with. Requiring
+      # support/artifice/compact_index already activates Artifice, so this
+      # must come first.
+      require "bundler/vendored_persistent"
       require "support/artifice/compact_index"
       Artifice.activate_with(CompactIndexAPI)
 

spec/support/artifice/helpers/artifice.rb

@@ -9,6 +9,14 @@ module Artifice
   # Rack endpoint.
   #
   # @param [#call] endpoint A valid Rack endpoint
+  # In-process users that also deactivate must load bundler/vendored_persistent
+  # before activating. If it gets lazily required while Artifice is active, the
+  # vendored Persistent classes are defined under the Artifice replacement of
+  # Gem::Net::HTTP instead of the real one, and after deactivation
+  # Gem::Net::HTTP::Persistent becomes unresolvable, blowing up the
+  # connection_pool fork hook on any later Process.fork. Spawned bundler
+  # processes are unaffected: they never deactivate, and requiring it here
+  # would double-load bundler files in them through mismatched load paths.
   def self.activate_with(endpoint)
     require_relative "rack_request"