pg_rewind tap test unstable

Hi,

for something between 10% and 20% of the devel builds for apt.postgresql.org
(which happen every 6h if there's a git change, so it happens every few days),
I'm seeing this:

make[2]: Entering directory '/tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/src/bin/pg_rewind'
rm -rf /tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/../src/bin/pg_rewind/tmp_check/log
cd /tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/../src/bin/pg_rewind && TESTDIR='/tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/src/bin/pg_rewind' PATH="/tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/tmp_install/usr/lib/postgresql/9.6/bin:$PATH" LD_LIBRARY_PATH="/tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/tmp_install/usr/lib/x86_64-linux-gnu" PGPORT='65432' top_builddir='/tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/src/bin/pg_rewind/../../..' prove -I /tmp/buildd/postgresql-9.6-9.6~~devel~20150728.0405/build/../src/test/perl/ --verbose t/*.pl

# Failed test 'tail-copy: query result matches'
# at RewindTest.pm line 131.
# got: '1
# '
# expected: '10001
# '
# Looks like you failed 1 test of 8.
t/001_basic.pl .......
1..8
ok 1 - pg_rewind local
ok 2 - table content: query result matches
ok 3 - truncation: query result matches
not ok 4 - tail-copy: query result matches
ok 5 - pg_rewind remote
ok 6 - table content: query result matches
ok 7 - truncation: query result matches
ok 8 - tail-copy: query result matches
Dubious, test returned 1 (wstat 256, 0x100)
Failed 1/8 subtests

I don't have the older logs available, but from memory, the subtest
failing and the two numbers mentioned are always the same.

Christoph
--
cb(at)df7cb(dot)de | http://www.df7cb.de/