Capture Gemfile source location for each override

Bundler::Dsl#override now records caller_locations(1, 1).first on
each Override so the originating Gemfile line can be surfaced in
later diagnostics.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hsbt

bundler/lib/bundler/dsl.rb

@@ -201,8 +201,9 @@ def override(target, **operations)
         validate_override_uniqueness!(target, field)
       end
 
+      source_location = caller_locations(1, 1)&.first
       operations.each do |field, operation|
-        @overrides << Override.new(target, field, operation)
+        @overrides << Override.new(target, field, operation, source_location: source_location)
       end
     end
 

bundler/lib/bundler/override.rb

@@ -9,12 +9,18 @@ def self.find_for(overrides, name, field)
         overrides.find {|o| o.target == :all && o.field == field }
     end
 
-    attr_reader :target, :field, :operation
+    attr_reader :target, :field, :operation, :source_location
 
-    def initialize(target, field, operation)
+    def initialize(target, field, operation, source_location: nil)
       @target = target
       @field = field
       @operation = operation
+      @source_location = source_location
+    end
+
+    def source_location_label
+      return nil unless @source_location
+      "#{File.basename(@source_location.path)}:#{@source_location.lineno}"
     end
 
     def apply_to(requirement)