Reline.readline does not work if STDOUT is a tty and STDIN is not a tty

[tompng]

Description

In Mac, Reline crashes if stdout is a tty and stdin is not a tty. This behavior depends on environment. It works in CI. test_with_newline in test_rendering.rb passes.

% (printf 'hello') | ruby -rreline -e "p Reline.readline '> '"

# In macOS, Terminal.app, zsh
▽/Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline/ansi.rb:273:in `pread': not opened for reading (IOError)
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline/ansi.rb:273:in `rescue in cursor_pos'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline/ansi.rb:252:in `cursor_pos'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline.rb:498:in `may_req_ambiguous_char_width'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline.rb:311:in `inner_readline'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline.rb:287:in `readline'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/3.2.0/forwardable.rb:240:in `readline'
	from -e:1:in `<main>'
/Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline/ansi.rb:255:in `raw': Inappropriate ioctl for device (Errno::ENOTTY)
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline/ansi.rb:255:in `cursor_pos'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline.rb:498:in `may_req_ambiguous_char_width'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline.rb:311:in `inner_readline'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/reline-0.3.3/lib/reline.rb:287:in `readline'
	from /Users/tomoya/.rbenv/versions/3.2.0/lib/ruby/3.2.0/forwardable.rb:240:in `readline'
	from -e:1:in `<main>'

# Inside docker (docker run --rm -ti rubylang/rubyfarm sh)
> hello
"hello"

In the above example, it seems working in docker, but actually it's not.

# (printf 'he';sleep 1;printf 'llo') | ruby -rreadline -e "p Readline.readline '> '"
> hello
"hello"
# (printf 'he';sleep 1;printf 'llo') | ruby -rreline -e "p Reline.readline '> '"
> he
"he"
# ruby -v
ruby 3.3.0dev (2023-05-01T12:20:20Z master 13dfbcf7bf) [x86_64-linux]
# ruby -rreline -e "puts Reline::VERSION"
0.3.3

Terminal Emulator

macOS Terminal.app

[revolter]

Could this be the same error as:

bundler: failed to load command: fastlane (/Users/revolt/.gems/bin/fastlane)
/Users/revolt/.rbenv/versions/3.3.0/lib/ruby/3.3.0/reline/ansi.rb:238:in `winsize': [!] Operation not supported by device - <STDIN> (Errno::ENODEV)
	from /Users/revolt/.rbenv/versions/3.3.0/lib/ruby/3.3.0/reline/ansi.rb:238:in `get_screen_size'
	from /Users/revolt/.rbenv/versions/3.3.0/lib/ruby/3.3.0/reline.rb:218:in `get_screen_size'
	from /Users/revolt/.rbenv/versions/3.3.0/lib/ruby/3.3.0/forwardable.rb:240:in `get_screen_size'
	from /Users/revolt/.gems/gems/tty-screen-0.8.2/lib/tty/screen.rb:359:in `size_from_readline'
	from /Users/revolt/.gems/gems/tty-screen-0.8.2/lib/tty/screen.rb:111:in `size'
	from /Users/revolt/.gems/gems/tty-screen-0.8.2/lib/tty/screen.rb:129:in `width'
	from /Users/revolt/.gems/gems/fastlane-2.219.0/fastlane_core/lib/fastlane_core/ui/implementations/shell.rb:90:in `header'

?

It's only triggered when we:

• execute git commit
• which executes a pre-commit hook
• which executes a Python script
• which executes a fastlane lane
• which tries to execute TTY::Screen.width

cc @bpoplauschi

[forthrin]

1. Is the below the same problem as this issue?
2. When will the problem be patched via RubyGems?
3. Where can I find a patch to apply in the meantime?

$ echo Foo | xargs ruby -r readline -e "puts 'Bar'"
/opt/homebrew/lib/ruby/gems/3.3.0/gems/reline-0.5.0/lib/reline/ansi.rb:240:in `winsize': Operation not supported by device - <STDIN> (Errno::ENODEV)
	from /opt/homebrew/lib/ruby/gems/3.3.0/gems/reline-0.5.0/lib/reline/ansi.rb:240:in `get_screen_size'
	from /opt/homebrew/lib/ruby/gems/3.3.0/gems/reline-0.5.0/lib/reline/line_editor.rb:59:in `initialize'
	from /opt/homebrew/lib/ruby/gems/3.3.0/gems/reline-0.5.0/lib/reline.rb:553:in `new'

[vtamara]

On OpenBSD/adJ 7.4 I don't see the problem that @forthrin reports by running:

% echo Foo | xargs ruby -r readline -e "puts 'Bar'"
Bar

But I see the same error reline-0.5.3/lib/reline/ansi.rb:246:in 'winsize': Operation not supported by device - <STDIN> (Errno::ENODEV) described by him and by @revolter in a different scenario that I described in the issue #690.

[tompng]

#659 also adds rescue Errno::ENODEV

[kaoru]

I think we might be seeing the originally described bug "Reline.readline does not work if STDOUT is a tty and STDIN is not a tty" when working on a Rails app with hookup. Hookup automatically runs rake db:migrate and bundle install when switching branches, but it runs db:migrate with a closed STDIN and that causes this LoadError: cannot load such file -- readline.bundle (LoadError) to appear.

$ bin/rails db:migrate < /dev/null
bin/rails aborted!
Errno::ENODEV: Operation not supported by device - <STDIN> (Errno::ENODEV)
/Users/alex/Documents/Git/App/config/application.rb:8:in `<main>'
/Users/alex/Documents/Git/App/Rakefile:4:in `<main>'
bin/rails:4:in `<main>'

Caused by:
LoadError: cannot load such file -- readline.bundle (LoadError)
Did you mean?  readline
/Users/alex/Documents/Git/App/config/application.rb:8:in `<main>'
/Users/alex/Documents/Git/App/Rakefile:4:in `<main>'
bin/rails:4:in `<main>'
(See full trace by running task with --trace)

I have been able to reproduce this with a new rails app like so:

$ rails new rn7
$ cd rn7
$ bin/rails db:migrate < /dev/null

And removing the following line from the Gemfile fixes it:

gem "debug", platforms: %i[ mri windows ]

Which I think points to reline, as it is a dependency of the debug gem.

Adding the following line to the Gemfile:

gem "reline", git: 'https://github.com/tompng/reline', branch: 'ansi_is_general_io'

Seems to fix it, which points to #659 as being a good fix.

However, I've only tested that with empty/no-op db:migrate calls so I can't say for sure that it's working fully.

[kaoru]

This seems to be fixed in https://github.com/ruby/reline/releases/tag/v0.5.7 - bin/rails db:migrate < /dev/null is no longer throwing Errno::ENODEV: Operation not supported by device since we upgraded.

[tompng]

Original issue pread: not opened for reading is fixed in #671
The bin/rails db:migrate < /dev/null problem mentioned here is fixed in #703