Bump required ruby version to 2.5

since we broke 2.4 again (by Hash#transform_keys)

.appveyor.yml

@@ -31,6 +31,6 @@ environment:
       RUBYDOWNLOAD: x86
       PGVERSION: 10.16-1-windows
       PGVER: 10
-    - ruby_version: "24"
+    - ruby_version: "25"
       PGVERSION: 9.3.25-1-windows
       PGVER: 9.3

.github/workflows/binary-gems.yml

@@ -40,7 +40,7 @@ jobs:
           - ruby: "3.0"
             PGVERSION: 13.2-1-windows-x64
             PGVER: "13"
-          - ruby: "2.4"
+          - ruby: "2.5"
             PGVERSION: 10.16-1-windows
             PGVER: "10"
 

.github/workflows/source-gem.yml

@@ -34,7 +34,7 @@ jobs:
             PGVERSION: 13.2-1-windows-x64
             PGVER: "13"
           - os: windows
-            ruby: "2.4"
+            ruby: "2.5"
             PGVERSION: 9.3.25-1-windows-x64
             PGVER: "9.3"
           - os: ubuntu
@@ -44,7 +44,7 @@ jobs:
             ruby: "3.0"
             PGVER: "12"
           - os: ubuntu
-            ruby: "2.4"
+            ruby: "2.5"
             PGVER: "9.3"
           - os: ubuntu
             ruby: "truffleruby"

.travis.yml

@@ -17,7 +17,7 @@ matrix:
       script: |
         docker run --rm -t --network=host ruby-pg
 
-    - rvm: "2.4"
+    - rvm: "2.5"
       env:
         - "PGVERSION=9.3"
     - rvm: ruby-head

Rakefile.cross

@@ -291,7 +291,7 @@ CrossLibraries.each do |xlib|
 		RakeCompilerDock.sh <<-EOT, platform: platform
 			(cp build/gem/gem-*.pem ~/.gem/ || true) &&
 			bundle install --local &&
-			rake native:#{platform} pkg/#{$gem_spec.full_name}-#{platform}.gem MAKE="make -j`nproc`"
+			rake native:#{platform} pkg/#{$gem_spec.full_name}-#{platform}.gem MAKE="make -j`nproc`" RUBY_CC_VERSION=3.0.0:2.7.0:2.6.0:2.5.0
 		EOT
 	end
 	desc "Build the windows binary gems"

lib/pg/connection.rb

@@ -485,8 +485,7 @@ class PG::Connection
 			end
 			REDIRECT_CLASS_METHODS.each do |ali, (async, sync)|
 				singleton_class.remove_method(ali) if method_defined?(ali)
-				# TODO: send is necessary for ruby < 2.5
-				singleton_class.send(:alias_method, ali, enable ? async : sync )
+				singleton_class.alias_method(ali, enable ? async : sync )
 			end
 		end
 	end

pg.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.description   = "Pg is the Ruby interface to the PostgreSQL RDBMS. It works with PostgreSQL 9.3 and later."
   spec.homepage      = "https://github.com/ged/ruby-pg"
   spec.license       = "BSD-2-Clause"
-  spec.required_ruby_version = ">= 2.4"
+  spec.required_ruby_version = ">= 2.5"
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = "https://github.com/ged/ruby-pg"