Hi Simon, Thanks for the update, I can reproduce a similar failure on the build bot and one of my own machines. I’m looking into what might be causing it, I have something I want to try but not Sure yet it will solve it. I don’t need more information atm as I can reproduce the race condition by doing enough I/O. Thanks, Tamar From: Simon Peyton Jones Sent: Tuesday, January 17, 2017 08:13 To: Phyx Cc: ghc-devs Subject: Windows build Hi Tamar The current state of a clean Windows build has improved – but still has multiple failures.  See below Thanks for your work on this. I can send more details if that’d be helpful Simon Unexpected failures:    plugins/plugins07.run  plugins07 [bad exit code] (normal)    plugins/T10420.run     T10420 [bad exit code] (normal)    plugins/T10294a.run    T10294a [bad exit code] (normal)    plugins/T11244.run     T11244 [bad stderr] (normal) Framework failures:    backpack/cabal/bkpcabal03/bkpcabal03.run   bkpcabal03 [runTest] (Unhandled exception: [Errno 90] Directory not empty: 'autogen')    plugins/plugins07.run                      plugins07 [normal] (pre_cmd failed: 2)    plugins/T10420.run                         T10420 [normal] (pre_cmd failed: 2)    plugins/T10294a.run                        T10294a [normal] (pre_cmd failed: 2)    plugins/plugins07.run                      plugins07 [runTest] (Unhandled exception: [Errno 90] Directory not empty: 'rule-defining-plugin-0.1')    plugins/T11244.run                         T11244 [normal] (pre_cmd failed: 2)    safeHaskell/check/pkg01/ImpSafeOnly03.run  ImpSafeOnly03 [runTest] (Unhandled exception: [Errno 90] Directory not empty: 'safePkg01-1.0-COK8JB4prM8EuKYKd3XaX3')