[Haskell-cafe] Re: Problems installing HDBC-postgresql

[Martin Percossi]

Hi, sorry for the delay in replying.

You were right -- it was not finding the correct version of the library. 
  In fact, all I had to do was change the order in my LD_LIBRARY_PATH -- 
but thanks for the suggestion on strace -- I will certainly be using 
this tool for future problems.

Many thanks
Martin

John Goerzen wrote:
> On 2006-07-10, Martin Percossi <haskell-cafe at martinpercossi.com> wrote:
> 
>>Hi, I'm having problems using HDBC-postgresql (I've tried both 0.99.2.1 
>>and 1.0.0.0) with postgresql (version 8.1.4, installed in /share/pgsql). 
>>I adjust the include-dir and extra-lib-dirs to use the custom location 
>>of postgresql, and build: no error messages, everything seems fine.
> 
> 
> Probably, though, there is something that is not quite fine...
> 
> 
>>However, when I then try to type:
>>ghci -package HDBC -package HDBC-postgresql
>>, I get the error message:
>>Loading package HDBC-postgresql-0.99.2.1 ... linking ... ghc-6.4.2: 
>>/home/mpercossi/opt/lib/HDBC-postgresql-0.99.2.1/HSHDBC-postgresql-0.99.2.1.o: 
>>unknown symbol `PQserverVersion'
>>ghc-6.4.2: unable to load package `HDBC-postgresql-0.99.2.1'
> 
> 
> This sounds like it's not finding your PostgreSQL libraries.
> 
> First, can you confirm that PQserverVersion still occurs in your
> libpq-fe.h?
> 
> Next, try strace on your ghci session.
> 
> Grep for libpq in the output.  It may be instructive.
> 
> In my case, I saw:
> 
> stat64("/usr/lib/haskell-packages/ghc6/lib/HDBC-postgresql-0.99.2.1/libpq_dyn.so",
> 0xb763a1e0) = -1 ENOENT (No such file or directory)
> stat64("/usr/lib/haskell-packages/ghc6/lib/HDBC-postgresql-0.99.2.1/libpq.so",
> 0xb763a570) = -1 ENOENT (No such file or directory)
> open("/usr/lib/libpq.so", O_RDONLY)     = 3
> 
> So we know that the system did successfully open that library.
> 
> 
>>Has anyone seen this error message before? Google didn't turn up 
>>anything relevant to haskell -- however there does seem to be a 
>>PQserverVersion procedure in the libpq library -- maybe HDBC-postgresql 
>>is not seeing this due to the custom install location?
> 
> 
> This would all be up to your modifications to cabal.  
> 
> Try: ghc-pkg describe HDBC-postgresql
> 
> You should see:
> 
>  * pq in the extra-libraries line
>  * Your header file location in the include-dirs line
>  * Your extra-lib-dirs path
> 
> If you don't see those things, then something went wrong with the build
> or install.
> 
> I would also suggesting building a program with GHC (not GHCI) that uses
> HDBC-postgresql for testing.
> 
> -- John
> 
> 
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