On Thu, 13 Jun 2013, Steven Ayre wrote:
To answer your question of what the test is doing, it'll take the required flags/libs from pg_config (which it
looks like it found) and then try compiling a tiny program linking to it to check if the library exists and when
testing functions if that function is exported by that version of the library. Any compile error means 'no'.
That ac_ variable is checking if its 'set' which'd mean the test passed. Config.log will show all the tests
being run and any error output for them.
-Steve
Thank you very much. Most helpful!
I had only tail'ed config.log and further up I found:
configure:19550: checking for PostgreSQL libraries
configure:19584: checking for PQgetvalue in -lpq
configure:19619: gcc -o conftest -g -O2 conftest.c -lpq -lodbc >&5
/usr/bin/ld: cannot find -lpq
collect2: ld returned 1 exit status
configure:19626: $? = 1
So the linker is not able to find and include the library. The empty spaces after -O2 and -lpq might indicate that some empty variables might have been inserted.
>From configure I know that we can find pg_config:
checking for pg_config... /usr/pgsql-9.2/bin/pg_config
checking for PostgreSQL libraries... checking for PQgetvalue in -lpq... no
configure: error: no usable libpq; please install PostgreSQL devel package or equivalent
And from the shell I know I get the proper path:
$ pg_config --libdir
/usr/pgsql-9.2/lib
And from the configure script it looks like the correct parameter is used:
POSTGRESQL_LDFLAGS="`$PG_
CONFIG --ldflags` -L`$PG_CONFIG --libdir` -lpq"
It looks like these flags are not passed to gcc/ld when linking conftest.c
My conclusion is then that pg_config is found and the correct options and path are extracted but they are not used (ignored?) during testing. Or if they should be used - something even more serious is wrong.
If that conclusion is correct I will file a Jira. The fix should be trivial for people in the know. I cannot determine whether the libdir should be added during the test. Or if pg_config should be ignored completely and replaced with a simple -with-pgsql-lib=dir.
If I set LDFLAGS before I do a configure it works:
$ LDFLAGS="${LDFLAGS} -L/usr/pgsql-9.2/lib"
$ export LDFLAGS
$./configure --enable-core-pgsql-support
Configure then runs smoothly. Make does however fail but that is another issue I'll put in a seperate thread.
With LDFLAGS set the relevant part of config.log now looks like this:
configure:19604: checking for PQgetvalue in -lpq
configure:19639: gcc -o conftest -g -O2 -L/usr/pgsql-9.2/lib conftest.c -lpq -lodbc >&5
configure:19646: $? = 0
configure:19667: result: yes
Do you agree that this is a "proper" issue?
Kind Regards,
Claus Andersen