Upgrade to ruby 2.7.6

Ruby v2.7.6 is the latest version before v3.0 at the time of this writing and upgrading to v2.7.6 may encounter a breaking issue if the application uses libraries that depend on BigDecimal.

The problem

  undefined method `new' for BigDecimal:Class

The reason for the above error is since ruby v2.7, the bigdecimal gem is upgraded to v2.0 with a breaking change that drops BigDecimal.new support.

The solution

  • For app code, replace BigDecimal.new with BigDecimal()
- bd = BigDecimal.new(100)
+ bd = BigDecimal(100)
  • For app using database gem such as mysql2 with version older than v0.5, upgrade the gem to v5.0+ in Gemfile and run bundle update mysql2
- gem 'mysql2', '0.4.10'
+ gem 'mysql2', '0.5.4'
  • (Not-recommended) Lock bigdecimal to an older version before v2.0 if no other solutions work, for example
gem 'bigdecimal', '1.4.4'