[rubygems/rubygems] Only raise DSLError during Gemfile parsing when it's actually useful

DSLError prints the specific line in a Gemfile where the error was
raised. That's helpful when the error was explicitly raised by the
Gemfile DSL or, in the case it's implicitly raised, when the offending
code lives right in the Gemfile.

If it's an internal error, or something buried dowm in user code called
from the Gemfile, `DSLError` is not helpful since it hides the actual
culprit.

This commit tries to only raise `DSLError` in the cases mentioned above
and otherwise let the original error be raised.

https://github.com/rubygems/rubygems/commit/b30ff5a682

lib/bundler/dsl.rb

@@ -45,11 +45,15 @@ module Bundler
       with_gemfile(gemfile) do |current_gemfile|
         contents ||= Bundler.read_file(current_gemfile)
         instance_eval(contents, current_gemfile, 1)
-      rescue StandardError, ScriptError => e
+      rescue GemfileEvalError => e
-        message = "There was an error " \
+        message = "There was an error evaluating `#{File.basename current_gemfile}`: #{e.message}"
-          "#{e.is_a?(GemfileEvalError) ? "evaluating" : "parsing"} " \
+        raise DSLError.new(message, current_gemfile, e.backtrace, contents)
-          "`#{File.basename current_gemfile}`: #{e.message}"
+      rescue GemfileError, InvalidArgumentError, InvalidOption, DeprecatedError, ScriptError => e
-
+        message = "There was an error parsing `#{File.basename current_gemfile}`: #{e.message}"
+        raise DSLError.new(message, current_gemfile, e.backtrace, contents)
+      rescue StandardError => e
+        raise unless e.backtrace_locations.first.path == current_gemfile
+        message = "There was an error parsing `#{File.basename current_gemfile}`: #{e.message}"
         raise DSLError.new(message, current_gemfile, e.backtrace, contents)
       end
     end
@@ -215,7 +219,7 @@ module Bundler
     end
 
     def github(repo, options = {})
-      raise ArgumentError, "GitHub sources require a block" unless block_given?
+      raise InvalidArgumentError, "GitHub sources require a block" unless block_given?
       github_uri  = @git_sources["github"].call(repo)
       git_options = normalize_hash(options).merge("uri" => github_uri)
       git_source  = @sources.add_git_source(git_options)

lib/bundler/errors.rb

@@ -244,4 +244,6 @@ module Bundler
 
     status_code(39)
   end
+
+  class InvalidArgumentError < BundlerError; status_code(40); end
 end

lib/bundler/ruby_version.rb

@@ -23,7 +23,13 @@ module Bundler
       #   specified must match the version.
 
       @versions = Array(versions).map do |v|
-        op, v = Gem::Requirement.parse(normalize_version(v))
+        normalized_v = normalize_version(v)
+
+        unless Gem::Requirement::PATTERN.match?(normalized_v)
+          raise InvalidArgumentError, "#{v} is not a valid requirement on the Ruby version"
+        end
+
+        op, v = Gem::Requirement.parse(normalized_v)
         op == "=" ? v.to_s : "#{op} #{v}"
       end
 

spec/bundler/bundler/ruby_dsl_spec.rb

@@ -80,7 +80,7 @@ RSpec.describe Bundler::RubyDsl do
     context "with two requirements in the same string" do
       let(:ruby_version) { ">= 2.0.0, < 3.0" }
       it "raises an error" do
-        expect { subject }.to raise_error(ArgumentError)
+        expect { subject }.to raise_error(Bundler::InvalidArgumentError)
       end
     end
 
@@ -168,7 +168,7 @@ RSpec.describe Bundler::RubyDsl do
         let(:file_content) { "ruby-#{version}@gemset\n" }
 
         it "raises an error" do
-          expect { subject }.to raise_error(Gem::Requirement::BadRequirementError, "Illformed requirement [\"#{version}@gemset\"]")
+          expect { subject }.to raise_error(Bundler::InvalidArgumentError, "2.0.0@gemset is not a valid requirement on the Ruby version")
         end
       end
 

spec/bundler/install/gemfile_spec.rb

@@ -66,6 +66,31 @@ RSpec.describe "bundle install" do
     end
   end
 
+  context "when an internal error happens" do
+    let(:bundler_bug) do
+      create_file("bundler_bug.rb", <<~RUBY)
+        require "bundler"
+
+        module Bundler
+          class Dsl
+            def source(source, *args, &blk)
+              nil.name
+            end
+          end
+        end
+      RUBY
+
+      bundled_app("bundler_bug.rb").to_s
+    end
+
+    it "shows culprit file and line" do
+      skip "ruby-core test setup has always \"lib\" in $LOAD_PATH so `require \"bundler\"` always activates the local version rather than using RubyGems gem activation stuff, causing conflicts" if ruby_core?
+
+      install_gemfile "source 'https://gem.repo1'", requires: [bundler_bug], artifice: nil, raise_on_error: false
+      expect(err).to include("bundler_bug.rb:6")
+    end
+  end
+
   context "with engine specified in symbol", :jruby_only do
     it "does not raise any error parsing Gemfile" do
       install_gemfile <<-G