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EACCES error in Puma or while testing on Windows.

Fix

Sometimes a reload in the browser works, but not always. For Puma, change the line in config/puma.rb from ``` max_threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 } ``` to ``` max_threads_count = ENV.fetch("RAILS_MAX_THREADS") { 1 } ``` Puma appears to be thread unsafe in some circumstances. For testing, comment out the line ``` parallelize(workers: :number_of_processors) ``` in test/test\_helper.rb

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None of the paths included in TZInfo::DataSources::ZoneinfoDataSource.search_path are valid zoneinfo directories. (TZInfo::DataSources::ZoneinfoDirectoryNotFound)

Fix

Comment out part of the line ``` gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ] ``` so it looks like ``` gem "tzinfo-data" #, platforms: %i[ mingw mswin x64_mingw jruby ] ```

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An error occurred while installing psych (5.1.0), and Bundler cannot continue.

In Gemfile:
  debug was resolved to 1.8.0, which depends on
    irb was resolved to 1.8.1, which depends on
      rdoc was resolved to 6.5.0, which depends on
        psych

Fix

You need to install a YAML library: ``` sudo apt install libyaml-dev ``` or ``` apk install yaml-dev ```

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NameError: uninitialized constant Gem::Source

Fix

gem update --system

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When testing:

BooksLibrariesControllerTest#test_should_create_books_library: NameError: Rails couldn't find a valid model for BooksLibrary association.  Please provide the :class_name option on the association declaration. If :class_name is already provided, make sure it's an ActiveRecord::Base subclass.

Fix

Add a class\_name to the has\_many's before the has\_many through's class Book < ApplicationRecord has_many :books_libraries, class_name: "BooksLibraries" has_many :libraries, through: :books_libraries end class Library < ActiveRecord::Base has_many :books_libraries, class_name: "BooksLibraries" has_many :books, through: :books_libraries end class BooksLibraries < ApplicationRecord belongs_to :book belongs_to :library end I'm not really sure why this is required as it would seem the class name is obvious.

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