Re: [PING] fallocate() causes btrfs to never compress postgresql files - Mailing list pgsql-hackers

Andrew Dunstan <andrew@dunslane.net> writes:
> On 2026-02-06 Fr 10:11 AM, Tom Lane wrote:
>> The message is complaining that sizeof(ConfigureNamesEnum) changed,
>> which it did, but I don't see how that value would be visible to
>> external modules.  So maybe a bug in libabigail?

> I guess because of this in guc_tables.h:
> extern PGDLLIMPORT struct config_generic ConfigureNames[];

Evidently, but I don't see how that provides a sizeof() value to
onlookers.  Just to be sure, I tried to compile a use of that,
and got

test.c:43:53: error: invalid application of ‘sizeof’ to incomplete type ‘struct config_generic[]’
  elog(NOTICE, "sizeof(ConfigureNames) = %zu", sizeof(ConfigureNames));
                                                     ^

So if this isn't an outright bug, it's at least unhelpful behavior.

            regards, tom lane