Re: [RFC] building postgres with meson -v8

On 20.04.22 23:04, Andres Freund wrote:
>> 0003-Fix-warnings-about-deprecated-features.patch
>>
>> This fixes some deprecation warnings and raises the requirement to 0.56.
> 
> I don't see any deprecation warnings - I see some notices about *future*
> deprecated features being used:
> 
> NOTICE: Future-deprecated features used:
>   * 0.55.0: {'ExternalProgram.path'}
>   * 0.56.0: {'meson.source_root', 'meson.build_root'}
> 
> (i.e. once the minimum version is increased to > 0.54, those will trigger
> deprecation warnings)
> 
> What are you seeing with what version?

I see the same thing.  Effectively, "deprecation warning" and 
"future-deprecation notice" are just different spellings of "yelling at 
me unconditionally for using code that I can't do anything about".

>> I'm not sure why the current cutoff at 0.54 was chosen.  Perhaps that could
>> be documented.
> 
> Not quite sure why I ended up with 0.54. We definitely should require at most
> 0.56, as that's the last version supporting python 3.5.

Why is Python 3.5 relevant?

>>  From 1f80e1ebb8efeb0eba7d57032282520fd6455b0d Mon Sep 17 00:00:00 2001
>> From: Peter Eisentraut <peter@eisentraut.org>
>> Date: Wed, 13 Apr 2022 11:50:52 +0200
>> Subject: [PATCH 5/5] Workaround for Perl detection
>>
>> ---
>>   meson.build | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/meson.build b/meson.build
>> index 1bf53ea24d..e33ed11b08 100644
>> --- a/meson.build
>> +++ b/meson.build
>> @@ -545,9 +545,9 @@ else
>>     # file existence.
>>     if perl_may_work
>>       perl_ccflags += ['-I@0@'.format(perl_inc_dir)]
>> -    if host_machine.system() == 'darwin'
>> -      perl_ccflags += ['-iwithsysroot', perl_inc_dir]
>> -    endif
>> +    #if host_machine.system() == 'darwin'
>> +    #  perl_ccflags += ['-iwithsysroot', perl_inc_dir]
>> +    #endif
>>     endif
> 
> What problem do you see without this? It did build on CI and on my m1 mini box
> as is...

I'm using homebrew-installed gcc and homebrew-installed perl.  gcc 
doesn't understand the option -iwithsysroot, and apparently whatever it 
points to is not needed.

Note that in configure.ac the logic is like this:

   if test \! -f "$perl_archlibexp/CORE/perl.h" ; then
     if test -f "$PG_SYSROOT$perl_archlibexp/CORE/perl.h" ; then
       perl_includespec="-iwithsysroot $perl_archlibexp/CORE"
     fi
   fi

So it checks first if it can find the needed file without the sysroot 
business.