Bug #21211: Incomplete Backtrace for Socket Errors in Ruby 3.4+

• Status: Closed
• Assignee: shioimm (Misaki Shioi)
• Target version: -
• Backport: 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED

[ioquatix (Samuel Williams)]

When invoking Socket.tcp with an invalid hostname (e.g., "foo.bar") in Ruby 3.4, the error raised does not provide a complete backtrace indicating the original application code that made the call. This behavior differs from Ruby 3.3 where the backtrace includes the relevant context.

Steps to Reproduce:

Run the following code in an IRB session with Ruby 3.4.2:

require 'socket'
Socket.tcp("foo.bar", 80)

Observe the error output:

/opt/rubies/3.4.2/lib/ruby/3.4.0/socket.rb:955:in 'Addrinfo.getaddrinfo': getaddrinfo: nodename nor servname provided, or not known (Socket::ResolutionError)
  from /opt/rubies/3.4.2/lib/ruby/3.4.0/socket.rb:955:in 'Socket.resolve_hostname'
  from /opt/rubies/3.4.2/lib/ruby/3.4.0/socket.rb:711:in 'block (2 levels) in Socket.tcp_with_fast_fallback'

Expected Behavior:

The error backtrace should include the original application code that triggered the socket call, providing better context for debugging.

/Users/samuel/.rubies/ruby-3.1.6/lib/ruby/3.1.0/socket.rb:227:in `getaddrinfo': getaddrinfo: nodename nor servname provided, or not known (SocketError)                          
  from /Users/samuel/.rubies/ruby-3.1.6/lib/ruby/3.1.0/socket.rb:227:in `foreach'
  from /Users/samuel/.rubies/ruby-3.1.6/lib/ruby/3.1.0/socket.rb:632:in `tcp'
  from (irb):2:in `<main>'               
  from /Users/samuel/.rubies/ruby-3.1.6/lib/ruby/gems/3.1.0/gems/irb-1.4.1/exe/irb:11:in `<top (required)>'
  from /Users/samuel/.rubies/ruby-3.1.6/bin/irb:25:in `load'
  from /Users/samuel/.rubies/ruby-3.1.6/bin/irb:25:in `<main>'

The change in how error backtraces are reported in Ruby 3.4 diminishes the ability to trace errors to user-level code, impacting debugging efforts. Can we restore or improve the backtrace reporting for socket-related errors.

[ioquatix (Samuel Williams)]

• Description updated (diff)

[byroot (Jean Boussier)]

• Backport changed from 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN to 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED

https://github.com/ruby/ruby/pull/13041

[byroot (Jean Boussier)]

• Status changed from Open to Closed

Applied in changeset git|580aa60051773e3512121088eb8ebaee8ce605ea.

---

Improve backtrace of errors raised by Socket.tcp_with_fast_fallback

[Bug #21211]

Socket errors raised from background threads are hard to track down because
their backtrace starts from the spawned thread.

To solve this we can raise a new error with the old one as cause.