libs found with check_lib should be added to LIBS - close #79

build_tests/configure/check_lib_success.rb

@@ -1,3 +1,9 @@
 configure do
   check_lib "m"
 end
+
+build do
+  Environment.new(echo: :command) do |env|
+    env.Program("simple.exe", "simple.c")
+  end
+end

lib/rscons/configure_op.rb

@@ -178,6 +178,9 @@ module Rscons
       }
       command = Environment.new.build_command("${LDCMD}", vars)
       _, _, status = log_and_test_command(command)
+      if status == 0
+        store_append({"LIBS" => [lib]}, options)
+      end
       common_config_checks(status, options)
     end
 

spec/build_tests_spec.rb

@@ -1773,6 +1773,15 @@ EOF
         expect(result.status).to eq 0
         expect(result.stdout).to match /Checking for library 'mfoofoo'... not found/
       end
+
+      it "links against the checked library by default" do
+        test_dir "configure"
+        result = run_rscons(rsconscript: "check_lib_success.rb", op: "build")
+        expect(result.stderr).to eq ""
+        expect(result.status).to eq 0
+        expect(result.stdout).to match /Checking for library 'm'... found/
+        expect(result.stdout).to match /gcc.*-lm/
+      end
     end
 
     context "check_program" do