Changes:

• Add an error message when adding a gem with bundle add that's already in the bundle (#6341, @agrim123)
• Add Homepage, Source Code and Changelog URI metadata fields to the bundle gem gemspec template (@walf443)

Bugfixes:

• Fix issue where updating a gem resulted in the gem's version being downgraded when BUNDLE_ONLY_UPDATE_TO_NEWER_VERSIONS was set (#6529, @theflow)
• Fix some rescue calls that don't specifiy error type (@utilum)
• Fix an issue when the Lockfile would contain platform-specific gems that it didn't need (#6491, @segiddins)
• Improve handling of adding new gems with only a single group to the Gemfile in bundle add (@agrim123)
• Refactor check for OpenSSL in bundle env (@voxik)
• Remove an unnecessary assignment in Metadata (@voxik)

Documentation:

• Update docs to reflect revised guidance to check in Gemfile.lock into version control for gems (#5879, @arbonap)
• Add documentation for the --all flag in bundle update (@agrim123)
• Update README to use bundle add in usage examples (@hdf1986)