Why faraday dependency not being resolved by bundler? - ruby-on-rails-5.1

Question

I added gem 'bitfinex-rb' in rails gem file, When I do bundle install, I got below mentioned error:
Bundler could not find compatible versions for gem "faraday":
In snapshot (Gemfile.lock):
faraday (= 0.14.0)
In Gemfile:
bitfinex-rb was resolved to 0.1.0, which depends on
faraday (>= 0.9.2, ~> 0.9.2)
kucoin was resolved to 0.1.1, which depends on
faraday (>= 0.13)
Running `bundle update` will rebuild your snapshot from scratch, using only the gems in your Gemfile, which may resolve the conflict.
I tried running bundle update but no luck, gives below error.
Bundler could not find compatible versions for gem "actionpack":
In Gemfile:
lograge (~> 0.3.1) was resolved to 0.3.6, which depends on
actionpack (>= 3)
pretender was resolved to 0.3.2, which depends on
actionpack
rails (~> 5.1.5) was resolved to 5.1.6, which depends on
actionpack (= 5.1.6)
rspec-rails (~> 3.6) was resolved to 3.7.2, which depends on
actionpack (>= 3.0)
simple_form was resolved to 4.0.1, which depends on
actionpack (>= 5.0)
Bundler could not find compatible versions for gem "actionview":
In Gemfile:
rails (~> 5.1.5) was resolved to 5.1.6, which depends on
actionview (= 5.1.6)
web-console was resolved to 3.6.2, which depends on
actionview (>= 5.0)
Bundler could not find compatible versions for gem "activemodel":
In Gemfile:
dynamoid (~> 2) was resolved to 2.2.0, which depends on
activemodel (>= 4)
paperclip (~> 5.3.0) was resolved to 5.3.0, which depends on
activemodel (>= 4.2.0)
rails (~> 5.1.5) was resolved to 5.1.6, which depends on
activemodel (= 5.1.6)
simple_form was resolved to 4.0.1, which depends on
activemodel (>= 5.0)
Bundler could not find compatible versions for gem "activerecord":
In Gemfile:
annotate was resolved to 2.7.4, which depends on
activerecord (< 6.0, >= 3.2)
rails (~> 5.1.5) was resolved to 5.1.6, which depends on
activerecord (= 5.1.6)
rails-erd was resolved to 1.5.2, which depends on
activerecord (>= 3.2)
Bundler could not find compatible versions for gem "activesupport":
In Gemfile:
bullet was resolved to 5.7.5, which depends on
activesupport (>= 3.0.0)
formulaic was resolved to 0.4.0, which depends on
activesupport
lograge (~> 0.3.1) was resolved to 0.3.6, which depends on
activesupport (>= 3)
paperclip (~> 5.3.0) was resolved to 5.3.0, which depends on
activesupport (>= 4.2.0)
rails (~> 5.1.5) was resolved to 5.1.6, which depends on
activesupport (= 5.1.6)
rails-erd was resolved to 1.5.2, which depends on
activesupport (>= 3.2)
rspec-rails (~> 3.6) was resolved to 3.7.2, which depends on
activesupport (>= 3.0)
shoulda-matchers was resolved to 3.1.2, which depends on
activesupport (>= 4.0.0)
spring was resolved to 2.0.2, which depends on
activesupport (>= 4.2)
time_difference was resolved to 0.7.0, which depends on
activesupport (~> 5.1)
Bundler could not find compatible versions for gem "aws-sdk-resources":
In Gemfile:
aws-sdk (= 2.10.47) was resolved to 2.10.47, which depends on
aws-sdk-resources (= 2.10.47)
dynamoid (~> 2) was resolved to 2.2.0, which depends on
aws-sdk-resources (~> 2)
Bundler could not find compatible versions for gem "faraday":
In Gemfile:
bitfinex-rb was resolved to 0.1.0, which depends on
faraday (>= 0.9.2, ~> 0.9.2)
kucoin was resolved to 0.1.1, which depends on
faraday (>= 0.13)
Bundler could not find compatible versions for gem "json":
In Gemfile:
bitfinex-rb was resolved to 0.1.0, which depends on
json (>= 1.8.3, ~> 1.8.3)
cryptocompare was resolved to 0.14.0, which depends on
json
simplecov was resolved to 0.16.1, which depends on
json (< 3, >= 1.8)
Bundler could not find compatible versions for gem "rails":
In Gemfile:
rails (~> 5.1.5)
devise_token_auth was resolved to 0.1.43, which depends on
rails (< 6)
sparkpost_rails was resolved to 1.5.1, which depends on
rails (< 5.3, >= 4.0)
suspenders was resolved to 1.45.0, which depends on
rails (~> 5.1.3)
title was resolved to 0.0.7, which depends on
rails (>= 3.1)
Bundler could not find compatible versions for gem "railties":
In Gemfile:
devise_token_auth was resolved to 0.1.43, which depends on
devise (< 4.5, > 3.5.2) was resolved to 4.4.3, which depends on
railties (< 6.0, >= 4.1.0)
dotenv-rails was resolved to 2.5.0, which depends on
railties (< 6.0, >= 3.2)
factory_bot_rails was resolved to 4.10.0, which depends on
railties (>= 3.0.0)
jquery-rails was resolved to 4.3.3, which depends on
railties (>= 4.2.0)
lograge (~> 0.3.1) was resolved to 0.3.6, which depends on
railties (>= 3)
rails (~> 5.1.5) was resolved to 5.1.6, which depends on
railties (= 5.1.6)
rspec-rails (~> 3.6) was resolved to 3.7.2, which depends on
railties (>= 3.0)
sass-rails (~> 5.0) was resolved to 5.0.7, which depends on
railties (< 6, >= 4.0.0)
web-console was resolved to 3.6.2, which depends on
railties (>= 5.0)
Bundler could not find compatible versions for gem "ruby":
In Gemfile:
ruby
suspenders was resolved to 1.46.0, which depends on
ruby (>= 2.5.0)
I tried deleting Gemfile.lock and bundle installed but getting above long listed error. What can be the solution for this type of scenario. Thank you all.

Answer 1

This is because kucoin 0.1.1 requires faraday >= 0.13 and bitfinex-rb 0.1.0 requires faraday ~> 0.9.2 (so >= 0.9.2 and <= 0.10). At least in Ruby Gems there is no higher version of bitfinex-rb so that you could update it. And the other version of kucoin (0.1.0) also requires faraday >= 0.13. So you can not install both gems (kucoin and bitfinex-rb) at the same time, because of the dependency. Bundle try to resolve the dependencies, but it can only do it if it is possible.