pg_rewind test race condition..?

Heikki,
 Not sure if anyone else is seeing this, but I'm getting regression test failures when running the pg_rewind tests
prettyconsistently with 'make check'.  Specifically with "basic remote", I'm getting:
 

source and target cluster are on the same timeline
Failure, exiting
 in regress_log/pg_rewind_log_basic_remote.
 If I throw a "sleep(5);" into t/001_basic.pl before the call to RewindTest::run_pg_rewind($test_mode); then everything
worksfine.
 
 ./configure --silent --prefix="$INSTALL" --with-openssl --with-tcl --with-tclconfig=/usr/lib/tcl8.6 --with-perl
--enable-debug--enable-cassert --enable-tap-tests --with-gssapi
 
 Full unsuccessful pg_rewind_log_basic_remote output:
-----------------------------------------------------------------
waiting for server to start....LOG:  database system was shut down at 2015-04-28 13:46:34 EDT
LOG:  database system is ready to accept connectionsdone
server started
waiting for server to start....LOG:  database system was interrupted; last known up at 2015-04-28 13:46:35 EDT
LOG:  entering standby mode
LOG:  redo starts at 0/2000028
LOG:  consistent recovery state reached at 0/20000F8
LOG:  database system is ready to accept read only connections
LOG:  started streaming WAL from primary at 0/3000000 on timeline 1done
server started
server promoting
LOG:  received promote request
FATAL:  terminating walreceiver process due to administrator command
LOG:  invalid record length at 0/30EB410
LOG:  redo done at 0/30EB3A0
LOG:  last completed transaction was at log time 2015-04-28 13:46:37.540952-04
LOG:  selected new timeline ID: 2
LOG:  archive recovery complete
LOG:  database system is ready to accept connections
waiting for server to shut down....LOG:  received fast shutdown request
LOG:  aborting any active transactions
LOG:  shutting down
LOG:  database system is shut downdone
server stopped

source and target cluster are on the same timeline
Failure, exiting
waiting for server to start....LOG:  database system was shut down at 2015-04-28 13:46:39 EDT
LOG:  entering standby mode
LOG:  consistent recovery state reached at 0/3311438
LOG:  invalid record length at 0/3311438
LOG:  database system is ready to accept read only connections
LOG:  fetching timeline history file for timeline 2 from primary server
LOG:  started streaming WAL from primary at 0/3000000 on timeline 1
LOG:  replication terminated by primary server
DETAIL:  End of WAL reached on timeline 1 at 0/30EB410.
LOG:  new timeline 2 forked off current database system timeline 1 before current recovery point 0/3311438
LOG:  restarted WAL streaming at 0/3000000 on timeline 1
LOG:  replication terminated by primary server
DETAIL:  End of WAL reached on timeline 1 at 0/30EB410.
LOG:  new timeline 2 forked off current database system timeline 1 before current recovery point 0/3311438done
server started
LOG:  received immediate shutdown request
LOG:  received immediate shutdown request
-----------------------------------------------------------------
 Full successful pg_rewind_log_basic_remote output:

-----------------------------------------------------------------
waiting for server to start....LOG:  database system was shut down at 2015-04-28 13:54:04 EDT
LOG:  database system is ready to accept connectionsdone
server started
waiting for server to start....LOG:  database system was interrupted; last known up at 2015-04-28 13:54:05 EDT
LOG:  entering standby mode
LOG:  redo starts at 0/2000028
LOG:  consistent recovery state reached at 0/20000F8
LOG:  database system is ready to accept read only connections
LOG:  started streaming WAL from primary at 0/3000000 on timeline 1done
server started
server promoting
LOG:  received promote request
FATAL:  terminating walreceiver process due to administrator command
LOG:  invalid record length at 0/30EB410
LOG:  redo done at 0/30EB3A0
LOG:  last completed transaction was at log time 2015-04-28 13:54:07.547533-04
LOG:  selected new timeline ID: 2
LOG:  archive recovery complete
LOG:  database system is ready to accept connections
waiting for server to shut down....LOG:  received fast shutdown request
LOG:  aborting any active transactions
LOG:  shutting down
LOG:  database system is shut downdone
server stopped
The servers diverged at WAL position 0/30EB410 on timeline 1.
Rewinding from last common checkpoint at 0/30EB3A0 on timeline 1
Done!
waiting for server to start....LOG:  database system was interrupted while in recovery at log time 2015-04-28 13:54:08
EDT
HINT:  If this has occurred more than once some data might be corrupted and you might need to choose an earlier
recoverytarget.
 
LOG:  entering standby mode
LOG:  redo starts at 0/30EB368
LOG:  consistent recovery state reached at 0/3113788
LOG:  invalid record length at 0/3113788
LOG:  database system is ready to accept read only connections
LOG:  started streaming WAL from primary at 0/3000000 on timeline 2done
server started
LOG:  received immediate shutdown request
LOG:  unexpected EOF on standby connection
LOG:  received immediate shutdown request
-----------------------------------------------------------------
Thanks!
    Stephen