Ruby

Environment¶

Ruby 3.0.2 is installed on Fedora 34 from source.
'gem update' is conducted, and there are two versions of 'pathname' gems (0.2.0, default: 0.1.0) installed as follows.

> uname -a Linux localhost.localdomain 5.14.18-200.fc34.x86_64 #1 SMP Fri Nov 12 16:48:10 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux > ruby -v ruby 3.0.2p107 (2021-07-07 revision 0db68f0233) [x86_64-linux] > gem update --system > gem update > gem list ... pathname (0.2.0, default: 0.1.0) ... 

Code¶

The following files, Gemfile and config.ru, are placed in the same directory.

# Gemfile source 'https://rubygems.org/' gem 'rack' gem 'webrick' 

# config.ru class Application def call(env) status = 200 headers = { "Content-Type" => "text/html" } path = Dir.pwd() pathname1 = Pathname.new(path) require("pathname") pathname2 = Pathname.new(path) body = ["#{pathname1.absolute?} #{pathname2.absolute?}"] [status, headers, body] end end run Application.new 

Command¶

Web server starts using the following commands.

bundle config set --local path 'vendor/bundle' bundle install bundle exec rackup -s webrick 

• Output on the console

[2021-11-21 09:44:13] INFO WEBrick 1.7.0 [2021-11-21 09:44:13] INFO ruby 3.0.2 (2021-07-07) [x86_64-linux] [2021-11-21 09:44:13] INFO WEBrick::HTTPServer#start: pid=2770 port=9292 

Expected Result¶

Accessing localhost:9292 using a web browser , 'true true' is an expected result on the browser, because pathname1 and pathanme2 are generated from the same absolute path in the above code.

true true 

Actual Result¶

Accessing localhost:9292 shows the following messages on the browser and the console. After 'require("pathname")', Pathname.absolute?() retuns false, even if represents an absolute path.

• On the browser

true false 

• On the console

/home/toshihiro/Ruby3/lib/ruby/3.0.0/pathname.rb:20: warning: already initialized constant Pathname::TO_PATH /home/toshihiro/Ruby3/lib/ruby/gems/3.0.0/gems/pathname-0.2.0/lib/pathname.rb:20: warning: previous definition of TO_PATH was here /home/toshihiro/Ruby3/lib/ruby/3.0.0/pathname.rb:22: warning: already initialized constant Pathname::SAME_PATHS /home/toshihiro/Ruby3/lib/ruby/gems/3.0.0/gems/pathname-0.2.0/lib/pathname.rb:22: warning: previous definition of SAME_PATHS was here /home/toshihiro/Ruby3/lib/ruby/3.0.0/pathname.rb:34: warning: already initialized constant Pathname::SEPARATOR_LIST /home/toshihiro/Ruby3/lib/ruby/gems/3.0.0/gems/pathname-0.2.0/lib/pathname.rb:34: warning: previous definition of SEPARATOR_LIST was here /home/toshihiro/Ruby3/lib/ruby/3.0.0/pathname.rb:35: warning: already initialized constant Pathname::SEPARATOR_PAT /home/toshihiro/Ruby3/lib/ruby/gems/3.0.0/gems/pathname-0.2.0/lib/pathname.rb:35: warning: previous definition of SEPARATOR_PAT was here /home/toshihiro/Ruby3/lib/ruby/3.0.0/pathname.rb:41: warning: already initialized constant Pathname::ABSOLUTE_PATH /home/toshihiro/Ruby3/lib/ruby/gems/3.0.0/gems/pathname-0.2.0/lib/pathname.rb:41: warning: previous definition of ABSOLUTE_PATH was here 127.0.0.1 - - [21/Nov/2021:09:44:20 +0900] "GET / HTTP/1.1" 200 10 0.0339 

Segmentation fault¶

Moreover, press Ctrl-c to stop the Rack application, the application causes a segmentation fault.

The segmentation fault message is attached.

Notes¶

Uninstalling version 0.2.0 of pathname gem solves the problem above. Therefore, I guess having two versions of pathname gems causes this behavior.

gem uninstall pathname --version=0.2.0 

• Start the Rack application again

bundle exec rackup -s webrick 

• Output on the browser

The expected output is obtained on the browser, without warning messages on the console.

true true