Error messages should be written to stderr, not stdout

[jaredbeck]

Demonstration of issue, abbreviated

bundle outdated 2> /dev/null
Could not find activesupport-5.0.1 in any of the sources

We redirect stderr to /dev/null, but output is still produced. Bundler is printing to stdout.

See below for complete, executable demonstration.

Expected behavior

Errors are always printed to stderr, never to stdout.

Current behavior

Errors are printed to stdout. (sometimes? always?)

Analysis

POSIX requires stderr, so fixing this issue would only be a problem if bundler supports systems that are non-compliant.

Complete, executable demonstration of issue

mkdir demo && cd demo
cat <<EOF > Gemfile
> source 'https://rubygems.org'
> gem 'activesupport'
> EOF
bundle install
gem uninstall activesupport
bundle outdated 2> /dev/null
Could not find activesupport-5.0.1 in any of the sources
bundle -v
Bundler version 1.14.4

[jaredbeck]

I'd be happy to work on this if it's approved.

[segiddins]

This is already implemented in the Bundler 2-0-dev branch

[jaredbeck]

This is already implemented in the Bundler 2-0-dev branch

Thanks Samuel, I'll close this then.

[indirect]

Thanks for reporting this! We completely agree, but are constrained by our strong backwards compatibility promises to wait to ship this change until 2.0. I'm looking forward to it, though. :)

[jaredbeck]

.. constrained by our strong backwards compatibility promises to wait to ship this change until 2.0 ..

That's wise, André. I've built a few tools that parse output from bundler and I'm sure some assume stdout when they shouldn't. Switching output to a different FD is def. a breaking change.