Re: Three animals fail test-decoding-check on REL_10_STABLE

I wrote:
> So it appears that in v10,
> ./configure ... --enable-tap-tests ...
> make
> make install
> cd contrib/test_decoding
> make check
> fails due to failure to install test_decoding into the tmp_install
> tree, while it works in v11. Moreover, that's not specific to
> gaur: it happens on my Linux box too. I'm not very sure why only
> three buildfarm animals are unhappy --- maybe in the buildfarm
> context it requires a specific combination of options to show the
> problem.

While I think I've fixed this bug, I'm still quite confused about why
only some buildfarm animals showed the problem. Comparing log files,
it seems that the ones that were working were relying on having
done a complete temp-install at a higher level, while the ones that
were failing were trying to make a temp install from scratch in
contrib/test_decoding and hence seeing the bug. For example,
longfin's test-decoding-check log starts out

napshot: 2019-01-11 21:12:17

/Applications/Xcode.app/Contents/Developer/usr/bin/make -C ../../src/test/regress all
/Applications/Xcode.app/Contents/Developer/usr/bin/make -C ../../../src/port all
/Applications/Xcode.app/Contents/Developer/usr/bin/make -C ../backend submake-errcodes
make[3]: Nothing to be done for `submake-errcodes'.

while gaur's starts out

Snapshot: 2019-01-11 07:30:45

rm -rf '/home/bfarm/bf-data/REL_10_STABLE/pgsql.build'/tmp_install
/bin/sh ../../config/install-sh -c -d '/home/bfarm/bf-data/REL_10_STABLE/pgsql.build'/tmp_install/log
make -C '../..' DESTDIR='/home/bfarm/bf-data/REL_10_STABLE/pgsql.build'/tmp_install install >'/home/bfarm/bf-data/REL_10_STABLE/pgsql.build'/tmp_install/log/install.log 2>&1
make -j1 checkprep >>'/home/bfarm/bf-data/REL_10_STABLE/pgsql.build'/tmp_install/log/install.log 2>&1
make -C ../../src/test/regress all
make[1]: Entering directory `/home/bfarm/bf-data/REL_10_STABLE/pgsql.build/src/test/regress'
make -C ../../../src/port all
make[2]: Entering directory `/home/bfarm/bf-data/REL_10_STABLE/pgsql.build/src/port'
make -C ../backend submake-errcodes
make[3]: Entering directory `/home/bfarm/bf-data/REL_10_STABLE/pgsql.build/src/backend'
make[3]: Nothing to be done for `submake-errcodes'.

These two animals are running the same buildfarm client version,
and I don't see any relevant difference in their configurations,
so why are they behaving differently? Andrew, any ideas?

regards, tom lane