nudge_test failed with an extra "done" on appveyor

My newly-enabled-on-Windows test from i#1309 just failed with an extra "done" being printed -- but why??

https://ci.appveyor.com/project/DynamoRIO/dynamorio/build/1.0.1697

[00:05:49] 131/246 Test #125: code_api|client.nudge_test ...................................***Failed  Required regular expression not found.Regex=[^thank you for testing the client interface
[00:05:49] ?
[00:05:49] nudge delivered 10
[00:05:49] ?
[00:05:49] nudge delivered 11
[00:05:49] ?
[00:05:49] done
[00:05:49] ?
[00:05:49] $
[00:05:49] ]  2.47 sec
[00:05:49] thank you for testing the client interface
[00:05:49] nudge delivered 10
[00:05:49] nudge delivered 11
[00:05:49] done
[00:05:49] done