Re: AC_CHECK_LIB doesn't find existing, linkable libraries

[Braden McDaniel]

Harry Mangalam wrote:
> Hi All,
>
> salient points: 
> Linux xxx.xxx.uci.edu 2.6.8.1-4-amd64-k8-smp #1 SMP Fri Jan 14 
> 11:33:56 UTC 2005 x86_64 GNU/Linux
>
>
> config.log pointed me to a number of erroneous conditions which I've 
> now corrected.  However, I'm still experiencing the same problem. 
>
> That is, that a library that is found by ldconfig:
> 529 $ ldconfig -v |head
> ldconfig: Path `/lib64' given more than once
> ldconfig: Path `/usr/lib64' given more than once
> /usr/local/lib:
>         libnco_c++-2.9.9.so -> libnco_c++.so
>         libnco-2.9.9.so -> libnco.so
>         libdap++.so.1 -> libdap++.so.1.0
>         libnc-dods.so.1 -> libnc-dods.so.1.0      <------ this is it
>
> and which has the right symbols defined:
>
> 530 $ nm /usr/local/lib/libnc-dods.so.1 |grep nc_open
> 0000000000031540 T lnc_open
> 0000000000020830 T nc_open
>
> but it cannot be grokked by the configure script which is set up as 
> follows:
> configure.in:    AC_CHECK_LIB([nc-dods],[nc_open],,enable_dods=no)
>
>
> config.log reports:
> configure:24221: checking for nc_open in -lnc-dods
> configure:24251: gcc -o conftest -g -O2 -I/usr/local/include  
> -L/usr/local/lib  conftest.c -ldap++ -lnc-dods -ldap++  -
> /usr/bin/ld: cannot find -lnc-dods
> collect2: ld returned 1 exit status
>
> I'm afraid I'm flummoxed with this - any other hints?

You probably need to be linking with g++. Use AC_LANG_PUSH([C++]) before 
your instantiation of AC_CHECK_LIB (and AC_LANG_POP afterward).

Braden