Skip backtrace capture on internal validation exceptions

CHANGELOG.md

@@ -8,6 +8,7 @@
 * [#2683](https://github.com/ruby-grape/grape/pull/2683): Introduce `Grape::Util::Lazy::Base` for unified lazy-type dispatch - [@ericproulx](https://github.com/ericproulx).
 * [#2685](https://github.com/ruby-grape/grape/pull/2685): Skip `run_filters` and `endpoint_run_filters.grape` instrumentation when the filter list is empty - [@ericproulx](https://github.com/ericproulx).
 * [#2684](https://github.com/ruby-grape/grape/pull/2684): Readability refactors: case/when, guard clauses, small cleanups - [@ericproulx](https://github.com/ericproulx).
+* [#2687](https://github.com/ruby-grape/grape/pull/2687): Skip backtrace capture on internal validation exceptions - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 #### Fixes

lib/grape/exceptions/validation.rb

@@ -3,6 +3,8 @@
 module Grape
   module Exceptions
     class Validation < Base
+      EMPTY_BACKTRACE = [].freeze
+
       attr_reader :params, :message_key
 
       def initialize(params:, message: nil, status: nil, headers: nil)
@@ -16,6 +18,10 @@ def initialize(params:, message: nil, status: nil, headers: nil)
         end
 
         super(status:, message:, headers:)
+        # Pre-seed the backtrace so Ruby's raise skips capture. Validation errors are
+        # a hot path (raised per bad attribute) and end up as 400 Bad Request responses;
+        # backtraces here point into Grape internals and have no diagnostic value.
+        set_backtrace(EMPTY_BACKTRACE)
       end
 
       # Remove all the unnecessary stuff from Grape::Exceptions::Base like status

lib/grape/exceptions/validation_array_errors.rb

@@ -3,11 +3,15 @@
 module Grape
   module Exceptions
     class ValidationArrayErrors < Base
+      EMPTY_BACKTRACE = [].freeze
+
       attr_reader :errors
 
       def initialize(errors)
         super()
         @errors = errors
+        # Skip backtrace capture — see Grape::Exceptions::Validation for rationale.
+        set_backtrace(EMPTY_BACKTRACE)
       end
     end
   end