Re: Add a hint to the "WAL summaries are required" errors

Hi Fujii,

On Mon, Nov 9, 2026 at 7:40 PM Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
wrote:
> HINT: Make sure WAL summarization is enabled. Consider using a more
> recent backup as the basis for this incremental backup,
> or taking a new full backup.

Your wording is better, and the more recent backup option works. In
the five ways I found to hit this error, a full backup taken after the
missing summaries was a good basis: the incremental backup succeeded
and the combined cluster started with all rows, 22 of 22 runs. A
backup from before them failed with the same error in all 22 runs that
had missing summaries, and each time the DETAIL's LSN fell between the
two backups' start LSNs. With your hint applied to master it builds
without warnings, and pg_combinebackup's TAP test 007 passes.

One note on the first sentence: with summarize_wal off, the request
fails earlier with "incremental backups cannot be taken unless WAL
summarization is enabled" (3 of 3), so whoever sees this hint already
has it enabled and the sentence can only be about the past.

Regards,
Manu