Feat: output STDERR from the building process

spec/integration/build_spec.cr

@@ -72,6 +72,23 @@ describe "build" do
     end
   end
 
+  {% unless flag?(:win32) %}
+    it "reports warning without failing" do
+      File.write File.join(application_path, "src", "cli.cr"), <<-CODE
+      @[Deprecated]
+      def a
+      end
+      a
+      CODE
+
+      Dir.cd(application_path) do
+        err = run "shards build --no-color app"
+        err.should match(/eprecated/)
+        File.exists?(bin_path("app")).should be_true
+      end
+    end
+  {% end %}
+
   it "errors when no targets defined" do
     File.write File.join(application_path, "shard.yml"), <<-YAML
       name: build

spec/support/factories.cr

@@ -242,7 +242,7 @@ def tmp_path
   Shards::Specs.tmp_path
 end
 
-def run(command, *, env = nil)
+def run(command, *, env = nil, return_error = false)
   cmd_env = {
     "CRYSTAL_PATH" => Shards::Specs.crystal_path,
   }
@@ -255,7 +255,8 @@ def run(command, *, env = nil)
   status = Process.run(command, shell: true, env: cmd_env, output: output, error: error || Process::Redirect::Close)
 
   if status.success?
-    output.to_s.gsub("\r\n", "\n")
+    output = output.to_s.gsub("\r\n", "\n")
+    output + error.to_s
   else
     raise FailedCommand.new("command failed: #{command}", output.to_s.gsub("\r\n", "\n"), error.to_s.gsub("\r\n", "\n"))
   end

src/commands/build.cr

@@ -44,9 +44,12 @@ module Shards
         Log.debug { "#{Shards.crystal_bin} #{args.join(' ')}" }
 
         error = IO::Memory.new
-
         status = Process.run(Shards.crystal_bin, args: args, output: Process::Redirect::Inherit, error: error)
-        raise Error.new("Error target #{target.name} failed to compile:\n#{error}") unless status.success?
+        unless status.success?
+          raise Error.new("Error target #{target.name} failed to compile:\n#{error}")
+        else
+          STDERR << error if error.size > 0
+        end
       end
     end
   end