Test workaround

lib/sass/compiler/open3.rb

@@ -1,33 +1,19 @@
 # frozen_string_literal: true
 
-module Open3
-  alias_method :__popen_run, :popen_run
-
-  def popen_run(cmd, opts, child_io, parent_io)
-    pid = spawn(*cmd, opts)
+require 'fcntl'
 
-    begin
-      require 'fcntl'
-
-      child_io.each do |io|
-        flags = io.fcntl(Fcntl::F_GETFL)
-        io.fcntl(Fcntl::F_SETFL, flags | (Fcntl::O_NONBLOCK))
-        io.fcntl(Fcntl::F_SETFL, flags & (~Fcntl::O_NONBLOCK))
-      end
-    rescue
-    end
-
-    wait_thr = Process.detach(pid)
-    child_io.each(&:close)
-    result = [*parent_io, wait_thr]
-    if defined? yield
-      begin
-        return yield(*result)
-      ensure
-        parent_io.each(&:close)
-        wait_thr.join
-      end
+module Open3
+  _popen_run = instance_method(:popen_run)
+  define_method(:popen_run) do |cmd, opts, child_io, parent_io, &block|
+    child_io.each do |io|
+      flags = io.fcntl(Fcntl::F_GETFL)
+      io.fcntl(Fcntl::F_SETFL, flags | (Fcntl::O_NONBLOCK))
+      io.fcntl(Fcntl::F_SETFL, flags & (~Fcntl::O_NONBLOCK))
     end
-    result
+    _popen_run.bind(self).call(cmd, opts, child_io, parent_io, &block)
+  end
+  module_function :popen_run
+  class << self
+    private :popen_run
   end
 end