Issue #19640 has been updated by ioquatix (Samuel Williams). Merged in https://github.com/ruby/ruby/commit/0b2613f44309bddae45562c9f3a14ed43e56959b ---------------------------------------- Bug #19640: `IO#puts` can generate zero length iov which can cause rb_bug crash. https://bugs.ruby-lang.org/issues/19640#change-103069 * Author: ioquatix (Samuel Williams) * Status: Open * Priority: Normal * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: REQUIRED ---------------------------------------- In the fiber scheduler, `IO#puts ""` or `IO#puts nil` can generate a zero length `iov` which causes `io_binwritev_internal` to fail since the result is zero. We need to fix `IO#puts` so that it does not generate zero length writes, but also we fix `io_binwritev_internal` to handle this case more robustly. Fix: https://github.com/ruby/ruby/pull/7806/files -- https://bugs.ruby-lang.org/