From f83c5de6d54c5c6384effde51c02b34d798e5056 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Rodr=C3=ADguez?= <deivid.rodriguez@riseup.net>
Date: Sun, 26 Jun 2022 19:08:25 +0200
Subject: [PATCH] [rubygems/rubygems] Improve error message when
 `operating_system.rb` fails to load

Show an absolute path instead of an unhelpful relative path.

https://github.com/rubygems/rubygems/commit/f1eed36e2f
---
 lib/rubygems.rb                |  3 ++-
 test/rubygems/test_rubygems.rb | 15 +++++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index add4034837..0e71f7b50e 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -1323,8 +1323,9 @@ begin
 rescue LoadError
   # Ignored
 rescue StandardError => e
+  path = e.backtrace_locations.reverse.find {|l| l.path.end_with?("rubygems/defaults/operating_system.rb") }.path
   msg = "#{e.message}\n" \
-    "Loading the rubygems/defaults/operating_system.rb file caused an error. " \
+    "Loading the #{path} file caused an error. " \
     "This file is owned by your OS, not by rubygems upstream. " \
     "Please find out which OS package this file belongs to and follow the guidelines from your OS to report " \
     "the problem and ask for help."
diff --git a/test/rubygems/test_rubygems.rb b/test/rubygems/test_rubygems.rb
index 739a9985b0..e5c0a22caf 100644
--- a/test/rubygems/test_rubygems.rb
+++ b/test/rubygems/test_rubygems.rb
@@ -16,7 +16,7 @@ class GemTest < Gem::TestCase
     output = Gem::Util.popen(*ruby_with_rubygems_and_fake_operating_system_in_load_path(path), '-e', "'require \"rubygems\"'", { :err => [:child, :out] }).strip
     assert !$?.success?
     assert_includes output, "undefined local variable or method `intentionally_not_implemented_method'"
-    assert_includes output, "Loading the rubygems/defaults/operating_system.rb file caused an error. " \
+    assert_includes output, "Loading the #{operating_system_rb_at(path)} file caused an error. " \
     "This file is owned by your OS, not by rubygems upstream. " \
     "Please find out which OS package this file belongs to and follow the guidelines from your OS to report " \
     "the problem and ask for help."
@@ -53,16 +53,19 @@ class GemTest < Gem::TestCase
 
   def util_install_operating_system_rb(content)
     dir_lib = Dir.mktmpdir("test_operating_system_lib", @tempdir)
-    dir_lib_arg = File.join dir_lib
+    dir_lib_arg = File.join dir_lib, "lib"
 
-    dir_lib_rubygems_defaults_arg = File.join dir_lib_arg, "lib", "rubygems", "defaults"
-    FileUtils.mkdir_p dir_lib_rubygems_defaults_arg
+    operating_system_rb = operating_system_rb_at(dir_lib_arg)
 
-    operating_system_rb = File.join dir_lib_rubygems_defaults_arg, "operating_system.rb"
+    FileUtils.mkdir_p File.dirname(operating_system_rb)
 
     File.open(operating_system_rb, 'w') {|f| f.write content }
 
-    File.join dir_lib_arg, "lib"
+    dir_lib_arg
+  end
+
+  def operating_system_rb_at(dir)
+    File.join dir, "rubygems", "defaults", "operating_system.rb"
   end
 
   def ruby_with_rubygems_and_fake_operating_system_in_load_path(operating_system_path)