From 004fe0b142f168560e9b103fe38ac9ffcc115a60 Mon Sep 17 00:00:00 2001
From: dearblue <dearblue@gmx.com>
Date: Thu, 11 Sep 2025 22:53:03 +0900
Subject: [PATCH] Set up all GEMS before mruby core tasks definition

Until now, GEMs dependent on GEMs described in the build configuration file were loaded and set up after mruby core tasks were defined.
This caused an issue where, if C++ exceptions were enabled later by a dependent GEM, the necessary tasks for mruby core were not defined.

fixed https://github.com/mruby/mruby/issues/6615
---
 Rakefile           |  5 +++++
 lib/mruby/gem.rb   | 17 ++++++++++++++++-
 tasks/mrbgems.rake |  2 --
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/Rakefile b/Rakefile
index 4422f9688..5d8ba4945 100644
--- a/Rakefile
+++ b/Rakefile
@@ -17,6 +17,11 @@ require "mruby/build"
 MRUBY_CONFIG = MRuby::Build.mruby_config_path
 load MRUBY_CONFIG
 
+# set up all gems
+MRuby.each_target do
+  gems.setup(self) if enable_gems?
+end
+
 # load basic rules
 MRuby.each_target do |build|
   build.define_rules
diff --git a/lib/mruby/gem.rb b/lib/mruby/gem.rb
index 619621e7b..a11c9feda 100644
--- a/lib/mruby/gem.rb
+++ b/lib/mruby/gem.rb
@@ -401,7 +401,16 @@ module MRuby
         end
       end
 
-      def generate_gem_table build
+      def setup(build)
+        gemset = nil
+        begin
+          gemset_prev = gemset
+          self.each(&:setup)
+          gemset = self.setup_dependencies(build).keys.sort
+        end until gemset == gemset_prev
+      end
+
+      def setup_dependencies(build)
         gem_table = each_with_object({}) { |spec, h| h[spec.name] = spec }
 
         default_gems = {}
@@ -424,6 +433,12 @@ module MRuby
           end
         end
 
+        gem_table
+      end
+
+      def generate_gem_table(build)
+        gem_table = setup_dependencies(build)
+
         each do |g|
           g.dependencies.each do |dep|
             name = dep[:gem]
diff --git a/tasks/mrbgems.rake b/tasks/mrbgems.rake
index 272d476e6..291bea615 100644
--- a/tasks/mrbgems.rake
+++ b/tasks/mrbgems.rake
@@ -2,8 +2,6 @@ MRuby.each_target do
   active_gems_txt = "#{build_dir}/mrbgems/active_gems.txt"
 
   if enable_gems?
-    # set up all gems
-    gems.each(&:setup)
     gems.check self
 
     # loader all gems