PostgreSQL on focal and llvm version

Re: hubert depesz lubaczewski
> Soo... plot thickens.
>
> Looks that pg 12 supplied by pgdg required libllvm9:
>
> =$ apt-cache show postgresql-12 | grep -E '^(Package|Version|Depends):'
> Package: postgresql-12
> Version: 12.9-2.pgdg20.04+1
> Depends: ..., libllvm9 (>= 1:9~svn298832-1~), ...
>
> Package: postgresql-12
> Version: 12.9-0ubuntu0.20.04.1
> Depends: ..., libllvm10 (>= 1:9~svn298832-1~), ...
>
> Package: postgresql-12
> Version: 12.2-4
> Depends: ..., libllvm10 (>= 1:9~svn298832-1~), ...
>
>
> Newer pg12 (12.10) from pgdg also depends on llvm9. Perhaps changing the deb to
> use/depend-on llvm10 would solve the problem, for now I'm not sure how to do
> it. Reached to Christoph about it.

Thanks for spotting that. The problem turned out me being not smart
enough to determine the newest llvm version installed; the
not-quite-correct Makefile code failed on "9" < "10".

I have now fixed that problem. Updated postgresql-{11,12,13,14}
packages using libllvm10 instead of libllvm9 are available in
focal-pgdg-testing.

Since this is potentially a breaking change, I'll not push these live
immediately but will give people a chance to test these until next
week.

Christoph