How to resolve BigDecimal 'already initialised constant' warnings on 'mailcatcher' cmd?

Question

Every time I start mailcatcher I'm shown 'already initialised constant' warnings. Can anyone advise how to resolve the issue? Thanks. Update below.

/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::BASE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::EXCEPTION_ALL
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::EXCEPTION_NaN
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::EXCEPTION_INFINITY
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::EXCEPTION_UNDERFLOW
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::EXCEPTION_OVERFLOW
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::EXCEPTION_ZERODIVIDE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_MODE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_UP
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_DOWN
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_HALF_UP
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_HALF_DOWN
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_CEILING
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_FLOOR
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::ROUND_HALF_EVEN
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_NaN
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_POSITIVE_ZERO
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_NEGATIVE_ZERO
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_POSITIVE_FINITE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_NEGATIVE_FINITE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_POSITIVE_INFINITE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::SIGN_NEGATIVE_INFINITE
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::INFINITY
/Users/james/.rvm/gems/ruby-2.1.5/extensions/x86_64-darwin-13/2.1.0/bigdecimal-1.2.7/bigdecimal.bundle: warning: already initialized constant BigDecimal::NAN

Update: I've uninstalled gem bigdecimal and installed gem bigdecimal, no change. I've then specified gem 'bigdecimal', ~> 1.1, still no change. Not much around on searches for this error. I'm running Ruby 2.1.5 and Rails 4.2.1.

Answer 1

It may be a problem with the bigdecimal gem. Try forcing v1.1 in your Gemfile:

gem 'bigdecimal', '~> 1.1'

From this answer.