ruby/rubygems · error · Bundler::GemNotFound

Could not find gem '#{missing_gem_name}'.

Error message

Could not find gem '#{missing_gem_name}'.

What it means

Error "Could not find gem '#{missing_gem_name}'." thrown in ruby/rubygems.

Source

Thrown at lib/bundler/cli/common.rb:87

      specs = []
      regexp = Regexp.new(name) if regex_match

      Bundler.definition.specs.each do |spec|
        return spec if spec.name == name
        specs << spec if regexp && spec.name.match?(regexp)
      end

      default_spec = default_gem_spec(name)
      specs << default_spec if default_spec

      case specs.count
      when 0
        dep_in_other_group = Bundler.definition.current_dependencies.find {|dep|dep.name == name }

        if dep_in_other_group
          raise GemNotFound, "Could not find gem '#{name}', because it's in the #{verbalize_groups(dep_in_other_group.groups)}, configured to be ignored."
        else
          raise GemNotFound, gem_not_found_message(name, Bundler.definition.dependencies)
        end
      when 1
        specs.first
      else
        ask_for_spec_from(specs)
      end
    rescue RegexpError
      raise GemNotFound, gem_not_found_message(name, Bundler.definition.dependencies)
    end

    def self.default_gem_spec(name)
      gem_spec = Gem::Specification.find_all_by_name(name).last
      gem_spec if gem_spec&.default_gem?
    end

    def self.ask_for_spec_from(specs)
      specs.each_with_index do |spec, index|
        Bundler.ui.info "#{index.succ} : #{spec.name}", true

View on GitHub (pinned to 86cbb817a3)

When it happens

Trigger: Thrown at lib/bundler/cli/common.rb:87 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ruby/rubygems@86cbb817a3 (2026-08-23). Data as JSON: /api/errors/2651547ac88cb489. Report an issue: GitHub.