Re: [RFC] building postgres with meson

Hi Andres,

> What do those extensions use to build? Since the unconference I added some
> rudimentary PGXS compatibility, but it's definitely not complete yet.

We mostly use CMake and Cargo, the Rust package manager. So I don't
anticipate many problems here, just want to make sure it's going to
work as expected.

> > ```
> > ../src/include/parser/kwlist.h:332:25: error: ‘PARAMETER’ undeclared here (not
> > in a function)
> > 332 | PG_KEYWORD("parameter", PARAMETER, UNRESERVED_KEYWORD, BARE_LABEL)
> >
> > ../src/interfaces/ecpg/preproc/keywords.c:32:55: note: in definition of macro
> > ‘PG_KEYWORD’
> > 32 | #define PG_KEYWORD(kwname, value, category, collabel) value,
> > ```
>
> Huh. I've not seen this before - could you provide a bit more detail about
> what you did? CI isn't testing ubuntu, but it is testing Debian, so I'd expect
> this to work.

I used PIP to install Meson, since the default APT package is too old, v0.53:

$ pip3 install --user meson
$ meson --version
0.62.1
$ ninja --version
1.10.0

The branch was checked out as it was described in the first email.
Then to reproduce the issue:

$ git status
On branch meson
Your branch is up to date with 'andres/meson'.
$ git fetch andres
$ git rebase -i andres/meson
$ meson setup build --buildtype debug
$ cd build
$ ninja

This is pretty much the default Ubuntu 20.04.4 LTS system with all the
recent updates installed, so it shouldn't be a problem to reproduce
the issue with a VM.

> > On MacOS I got multiple errors regarding LDAP:
>
> Ah, yes. Sorry, that's an open issue that I need to fix. -Dldap=disabled for
> the rescue. There's some crazy ordering dependency in macos framework
> headers. The ldap framework contains an "ldap.h" header that includes
> "ldap.h". So if you end up with the framework on the include path, you get
> endless recursion.

Thanks, this helped. I did the following:

$ meson configure -Dldap=disabled
$ meson configure -Dssl=openssl
$ meson configure -Dprefix=/Users/eax/pginstall
$ ninja
$ meson test
$ meson install

... and it terminated successfully. I was also able to configure and
run Postgres instance using my regular scripts, with some
modifications [1]

Then I decided to compile TimescaleDB against the newly installed
Postgres. Turns out there is a slight problem.

The extension uses CMake and also requires PostgreSQL to be compiled
with OpenSSL support. CMakeLists.txt looks for a
"--with-(ssl=)?openssl" regular expression in the "pg_config
--configure" output. The output is empty although Postgres was
compiled with OpenSSL support. The full output of pg_config looks like
this:

```
CONFIGURE =
CC = not recorded
CPPFLAGS = not recorded
CFLAGS = not recorded
CFLAGS_SL = not recorded
... etc ...
```

I get a bunch of errors from the compiler if I remove this particular
check from CMakeLists, but I have to investigate these a bit more
since the branch is based on PG15 and we don't officially support PG15
yet. It worked last time we checked a month or so ago, but the
situation may have changed.

[1]: https://github.com/afiskon/pgscripts/blob/master/single-install.sh

--
Best regards,
Aleksander Alekseev