diff --git a/lib/hbc/extend/io.rb b/lib/hbc/extend/io.rb
new file mode 100644
index 0000000000000..1357293cdcc84
--- /dev/null
+++ b/lib/hbc/extend/io.rb
@@ -0,0 +1,10 @@
+class IO
+  def readline_nonblock(sep = $INPUT_RECORD_SEPARATOR)
+    buffer = ""
+    buffer.concat(read_nonblock(1)) while buffer[-1] != sep
+    buffer
+  rescue IO::WaitReadable, EOFError => e
+    raise e if buffer.empty?
+    buffer
+  end
+end
diff --git a/lib/hbc/system_command.rb b/lib/hbc/system_command.rb
index 1b915f033dfa4..46b22f8f4bf12 100644
--- a/lib/hbc/system_command.rb
+++ b/lib/hbc/system_command.rb
@@ -1,3 +1,4 @@
+require "hbc/extend/io"
 require "open3"
 require "shellwords"
 
@@ -89,7 +90,11 @@ def each_line_from(sources)
       readable_sources = IO.select(sources)[0]
       readable_sources.delete_if(&:eof?).first(1).each do |source|
         type = (source == sources[0] ? :stdout : :stderr)
-        yield(type, source.gets || "")
+        begin
+          yield(type, source.readline_nonblock || "")
+        rescue IO::WaitReadable, EOFError
+          next
+        end
       end
       break if readable_sources.empty?
     end