Integration test failure by Errno::EIO on Linux

[mrkn]

  1) Error:
IntegrationTest#test_interaction:
Errno::EIO: Input/output error @ io_fillbuf - fd:7 /dev/pts/1
    /usr/local/lib/ruby/2.5.0/expect.rb:47:in `eof?'
    /usr/local/lib/ruby/2.5.0/expect.rb:47:in `expect'
    /iruby/test/integration_test.rb:27:in `expect'
    /iruby/test/integration_test.rb:11:in `setup'