Re: improve CREATE EXTENSION error message

> On 29 Nov 2021, at 22:02, Tom Lane  wrote:
> 
> "Bossart, Nathan"  writes:
>> Currently, if you attempt to use CREATE EXTENSION for an extension
>> that is not installed, you'll see something like the following:
> 
>>        postgres=# CREATE EXTENSION does_not_exist;
>>        ERROR:  could not open extension control file "/usr/local/pgsql/share/extension/does_not_exist.control": No such file or directory
> 
>> I suspect this ERROR message is confusing for novice users, so perhaps
>> we should add a HINT.
> 
> If we issue the hint only for errno == ENOENT, I think we could be
> less wishy-washy (and if it's not ENOENT, the hint is likely
> inappropriate anyway).  I'm thinking something more like
> 
> HINT:  This means the extension is not installed on the system.
> 
> I'm not quite satisfied with the "on the system" wording, but I'm
> not sure of what would be better.  I agree that we can't just say
> "is not installed", because people will confuse that with whether
> it is installed within the database.

That's a good point, the hint is targeting users who might not even know that
an extension needs to be physically and separately installed on the machine
before it can be installed in their database; so maybe using "installed" here
isn't entirely helpful at all.  That being said I'm at a loss for a more
suitable word, "available" perhaps?

--
Daniel Gustafsson		https://vmware.com/