ci: add dummy-mysql for OR dependency

compose.yaml

@@ -68,7 +68,7 @@ services:
     volumes:
       - .:/host:delegated
     command:
-      /host/dockerfiles/run-test.sh dummy-cairo
+      /host/dockerfiles/run-test.sh dummy-cairo dummy-mysql
 
   conda:
     build:

test/fixture/dummy-mysql/dummy-mysql.gemspec

@@ -0,0 +1,34 @@
+# -*- ruby -*-
+#
+# Copyright (C) 2025  Ruby-GNOME Project Team
+#
+# This library is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Gem::Specification.new do |spec|
+  spec.name = "dummy-mysql"
+  spec.version = "1.0.0"
+  spec.authors = ["Sutou Kouhei"]
+  spec.email = ["[email protected]"]
+  spec.licenses = ["LGPL-3.0-or-later"]
+  spec.summary = "Dummy gem that uses MySQL"
+  spec.description = "This is for testing rubygems-requirements-system"
+  spec.extensions = ["ext/dummy-mysql/extconf.rb"]
+  spec.files = ["ext/dummy-mysql/extconf.rb"]
+
+  spec.add_runtime_dependency("rubygems-requirements-system")
+
+  spec.requirements << "system: mysqlclient|libmariadb: arch_linux: mariadb-libs"
+  spec.requirements << "system: mysqlclient|libmariadb: debian: libmysqlclient-dev"
+  spec.requirements << "system: mysqlclient|libmariadb: debian: libmariadb-dev"
+end

test/fixture/dummy-mysql/ext/dummy-mysql/extconf.rb

@@ -0,0 +1,24 @@
+# Copyright (C) 2025  Ruby-GNOME Project Team
+#
+# This library is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+require "mkmf"
+
+require "pkg-config"
+
+if PKGConfig.have_package("mysqlclient") or PKGConfig.have_package("libmariadb")
+  create_makefile("dummy_mysql")
+else
+  exit(false)
+end