Testsuite failures from validate --slow

In case it helps, I ran a ./validate --slow on HEAD on Ubuntu Bionic with 8.6.1. I don't attach much weight to the performance / stat failures as the tests seem to run in parallel. I'll pull out more specific diagnostics, if necessary.

==== STAGE 1 TESTS ==== 

SUMMARY for test run started at Wed Oct 10 20:29:33 2018 BST
 0:00:04 spent to go through
       2 total tests, which gave rise to
      10 test cases, of which
       0 were skipped

       0 had missing libraries
      10 expected passes
       0 expected failures

       0 caused framework failures
       0 caused framework warnings
       0 unexpected passes
       0 unexpected failures
       0 unexpected stat failures

==== STAGE 2 TESTS ==== 

Unexpected results from:
TEST="EtaExpandLevPoly T14936 T15349 T2783 T4334 T7919 haddock.Cabal haddock.base haddock.compiler hpc_fork plugin-recomp-change plugin-recomp-change-prof recomp007 space_leak_001"

SUMMARY for test run started at Wed Oct 10 19:31:20 2018 BST
 0:58:10 spent to go through
    6596 total tests, which gave rise to
   29689 test cases, of which
    5881 were skipped

     256 had missing libraries
   23273 expected passes
     257 expected failures

       0 caused framework failures
       0 caused framework warnings
       3 unexpected passes
       6 unexpected failures
      13 unexpected stat failures

Unexpected passes:
   /tmp/ghctest-kyex1v3_/test   spaces/rts/T2783.run                              T2783 [unexpected] (threaded1)
   /tmp/ghctest-kyex1v3_/test   spaces/typecheck/should_run/EtaExpandLevPoly.run  EtaExpandLevPoly [unexpected] (profasm)
   /tmp/ghctest-kyex1v3_/test   spaces/typecheck/should_run/EtaExpandLevPoly.run  EtaExpandLevPoly [unexpected] (profthreaded)

Unexpected failures:
   /tmp/ghctest-kyex1v3_/test   spaces/driver/recomp007/recomp007.run         recomp007 [bad stderr] (normal)
   /tmp/ghctest-kyex1v3_/test   spaces/plugins/plugin-recomp-change.run       plugin-recomp-change [bad stderr] (normal)
   /tmp/ghctest-kyex1v3_/test   spaces/plugins/plugin-recomp-change-prof.run  plugin-recomp-change-prof [bad stderr] (normal)
   /tmp/ghctest-kyex1v3_/test   spaces/rts/T7919.run                          T7919 [bad exit code] (ghci)
   /tmp/ghctest-kyex1v3_/test   spaces/libraries/hpc/tests/fork/hpc_fork.run  hpc_fork [bad heap profile] (profasm)
   /tmp/ghctest-kyex1v3_/test   spaces/libraries/base/tests/T15349.run        T15349 [bad exit code] (ghci)

Unexpected stat failures:
   /tmp/ghctest-kyex1v3_/test   spaces/perf/haddock/haddock.base.run        haddock.base [stat not good enough] (normal)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/haddock/haddock.Cabal.run       haddock.Cabal [stat not good enough] (normal)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/haddock/haddock.compiler.run    haddock.compiler [stat not good enough] (normal)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/should_run/T14936.run           T14936 [stat not good enough] (hpc)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/should_run/T14936.run           T14936 [stat not good enough] (profasm)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/space_leaks/space_leak_001.run  space_leak_001 [stat too good] (hpc)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/space_leaks/space_leak_001.run  space_leak_001 [stat too good] (optasm)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/space_leaks/T4334.run           T4334 [stat not good enough] (threaded2)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/space_leaks/space_leak_001.run  space_leak_001 [stat too good] (dyn)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/space_leaks/space_leak_001.run  space_leak_001 [stat too good] (optllvm)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/should_run/T14936.run           T14936 [stat not good enough] (threaded1)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/should_run/T14936.run           T14936 [stat not good enough] (threaded2)
   /tmp/ghctest-kyex1v3_/test   spaces/perf/should_run/T14936.run           T14936 [stat not good enough] (profthreaded)

== Start post-testsuite package check
GHC package manager version 8.7.20181010
Timestamp 2018-10-10 18:31:15.21573855 UTC for /home/jrp/Projects/ghc/bindisttest/install   dir/lib/ghc-8.7.20181010/package.conf.d/package.cache
using cache: /home/jrp/Projects/ghc/bindisttest/install   dir/lib/ghc-8.7.20181010/package.conf.d/package.cache
db stack: ["/home/jrp/.ghc/x86_64-linux-8.7.20181010/package.conf.d","/home/jrp/Projects/ghc/bindisttest/install   dir/lib/ghc-8.7.20181010/package.conf.d"]
flag db stack: ["/home/jrp/.ghc/x86_64-linux-8.7.20181010/package.conf.d","/home/jrp/Projects/ghc/bindisttest/install   dir/lib/ghc-8.7.20181010/package.conf.d"]
== End post-testsuite package check
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Oops!  Looks like you have some unexpected test results or framework failures.
Please fix them before pushing/sending patches.
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