Re: segfault tied to "IS JSON predicate" commit

On Sat, Apr 15, 2023 at 4:11 PM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> $ meson test --setup tmp_install --list | grep install
> postgresql:setup / tmp_install
> postgresql:setup / install_test_files
>
> But not the running setup:
>
> $ meson test --setup running --list | grep install | wc -l
> 0

There is a concrete problem here: commit b6a0d469ca ("meson: Prevent
installation of test files during main install") overlooked "--setup
running". It did not add a way for the setup to run "postgresql:setup
/ install_test_files" (or perhaps something very similar).

The segfault must have been caused by unwitting use of a leftover
ancient test_rls_hooks.so from before commit b6a0d469ca. My old stale
.so must have continued to work for a little while, before it broke.
Now that I've fully deleted my install directory, I can see a clear
problem, which is much less mysterious than the segfault. Namely, the
following doesn't still work:

$ meson test --setup running --suite test_rls_hooks-running

This time it's not a segfault, though -- it's due to the .so being
unavailable. Adding "--suite setup" fixes nothing, since I'm using
"--setup running"; while the "--suite running" tests will actually run
and install the .so, they won't install it into the installation
directory I'm actually using (only into a tmp_install directory).
While I was wrong to implicate commit 6ee30209 (the IS JSON commit) at
first, there is a bug here. A bug in b6a0d469ca.

ISTM that b6a0d469ca has created an unmet need for a "--suite
setup-running", which is analogous to "--suite setup" but works with
"--setup running". That way there'd at least be a
"postgresql:setup-running / install_test_files" test that could be
used here, like so:

$ meson test --setup running --suite setup-running --suite
test_rls_hooks-running

But...maybe it would be better to find a way to install the stuff from
"postgresql:setup / install_test_files" in a less kludgy, more
standard kind of way? I see that the commit message from b6a0d469ca
says "there is no way to set up up the build system to install extra
things only when told". Is that *really* the case?

--
Peter Geoghegan