Re: Cygwin linking rules

On 09/29/2018 11:35 AM, Tom Lane wrote:
> Most of the buildfarm is now happy with the changes I made to have
> libpq + ecpg get src/port and src/common files via libraries ...
> but lorikeet isn't. It gets through the core regression tests fine
> (so libpq, per se, works), but contrib/dblink fails:
>
> ! ERROR: could not establish connection
> ! DETAIL: libpq is incorrectly linked to backend functions
>
> What this means is that libpq is calling the backend version of
> src/common/link-canary.c rather than the frontend version.
> Why would it do the right thing normally and the wrong thing in dblink?
>
> I can think of a few theories but I lack the ability to investigate:
>
> 1. Maybe the dblink.dll build is pulling in libpq.a rather than
> establishing a reference to libpq.dll. If so, the wrong things would
> happen because libpq.a won't contain the src/common/ files that
> libpq needs. (It seems like libpq.a is an active hazard given
> this. Why are we building it at all?)
>
> 2. Maybe we need a --version-script option or something equivalent
> to get libpq.dll's references to be preferentially resolved internally
> rather than to the backend. But this doesn't really explain why it
> worked properly before.
>
>

I will see if I can determine if 1) is the cause. I don't know enough,
or in fact anything, about 2), so don;t know that I can help there
without advice.

cheers

andrew

--
Andrew Dunstan https://www.2ndQuadrant.com
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