libyear-rb

A simple measure of dependency freshness for Ruby apps.

$ libyear-rb
Gem                  Current Current Date Latest   Latest Date Versions Days Years
.................... ....... ............ ........ ........... ........ .... .....
addressable          2.8.7   2024-06-21   2.8.8    2025-11-25         1  522  1.43
bigdecimal           3.3.1   2025-10-09   4.0.1    2025-12-17         4   69  0.19
rails                7.0.0   2021-12-15   7.2.0    2024-08-10        15  968  2.65
System is 4.27 libyears behind
Total releases behind: 20

libyear-rb tells you how out-of-date your Gemfile.lock is, in libyears (the time between your installed version and the newest version).

• Analyzes Gemfile.lock to measure dependency freshness
• Reports libyears (time behind) and version distance (releases behind)
• Supports any RubyGems.org-compatible gem server (private gem servers, mirrors, etc.)
• Historical analysis with --as-of to see what your dependencies looked like at a specific date
• Caches API responses to minimize network requests

gem install libyear-rb

Or add to your Gemfile:

gem "libyear-rb"

Run libyear-rb in a directory with a Gemfile.lock, or provide a path:

libyear-rb                      # Uses ./Gemfile.lock
libyear-rb path/to/Gemfile.lock # Uses specified lockfile

--as-of DATE    Analyze dependencies as of the given date (YYYY-MM-DD)
--verbose       Run with verbose logs
--help          Show help
--version       Show version

You can analyze what your dependencies looked like at a specific point in time:

libyear-rb --as-of 2024-01-01

libyear-rb supports any gem server with a RubyGems.org-compatible API. It uses your configured gem sources from ~/.gemrc or environment, so private gems hosted on servers like Gemfury, Artifactory, or self-hosted solutions work automatically.

To reduce API requests and improve performance, libyear-rb caches gem version metadata for 24 hours.

Cache location:

• Uses $XDG_CACHE_HOME/libyear-rb/ if XDG_CACHE_HOME is set
• Otherwise defaults to ~/.cache/libyear-rb/

Cache files are organized by gem source host, so metadata from different gem servers is stored separately.

To skip the cache:

SKIP_CACHE=1 libyear-rb

To clear the cache:

rm -rf ~/.cache/libyear-rb

Other Ruby tools for measuring dependency freshness:

• libyear-bundler - The original Ruby libyear implementation. Supports additional metrics like major/minor/patch version deltas and JSON output.
• bundler-audit - Focuses on security vulnerabilities rather than freshness, but useful for dependency health.
• bundle outdated - Built into Bundler. Shows outdated gems but doesn't calculate libyears.

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt.

To install this gem onto your local machine, run bundle exec rake install.

The concept of libyear comes from the technical report "Measuring Dependency Freshness in Software Systems" by J. Cox, E. Bouwers, M. van Eekelen and J. Visser (ICSE 2015).

The gem is available as open source under the terms of the MIT License.