[netCDF #AJV-500600]: Missing -ldl library when using hdf5-1.8.11 with netcdf-4.3.0 and configure

Greg,

> I think the issue is related to the use of a static hdf5 and/or netcdf
> library which is why it arises for you in the parallel case; I assume your
> serial testing only uses shareable hdf5/netcdf libraries.
> 
> In 1.8.11, hdf5 added the capability to use plugins which are dynamically
> loaded.  If linking with shareable libraries, then the -ldl is already
> present due to the mechanisms of shareable libraries; however, if using
> static libraries, the -ldl needs to be added manually which is not
> currently being done in configure.

Thanks for the explanation.  We'll get that fixed in the next release.

--Russ

> --Greg
> 
> On 6/5/13 2:37 PM, "Unidata netCDF Support"
> <address@hidden> wrote:
> 
> >Hi Greg,
> >
> >> When I try to use hdf5-1.8.11 with netcdf-4.3.0, the configure step
> >>fails when looking for the hdf5 library.  The configure test output is:
> >>
> >> configure:16229: gcc -o conftest -I../libsrc   -O
> >>-I/home/gdsjaar/src/SEACAS/inc  -m64 -DBuild64 -Dlinux  -DADDC_     -I./
> >> -I/home/gdsjaar/src/SEACAS/inc -fpic -DNDEBUG
> >>-L/home/gdsjaar/src/SEACAS/lib -m64    conftest.c -lhdf5  -lm -lz  >&5
> >> /home/gdsjaar/src/SEACAS/lib/libhdf5.a(H5PL.o): In function
> >>`H5PL__close':
> >> H5PL.c:(.text+0xd8): undefined reference to `dlclose'
> >> /home/gdsjaar/src/SEACAS/lib/libhdf5.a(H5PL.o): In function `H5PL_load':
> >> H5PL.c:(.text+0x3f2): undefined reference to `dlsym'
> >> H5PL.c:(.text+0x71a): undefined reference to `dlopen'
> >> H5PL.c:(.text+0x727): undefined reference to `dlerror'
> >> H5PL.c:(.text+0x73b): undefined reference to `dlsym'
> >> collect2: ld returned 1 exit status
> >> configure:16229: $? = 1
> >> configure: failed program was:
> >>
> >> If I add ­ldl to the library list, it then links correctly.  Do I need
> >>to pass some different option to configure, or is hdf5-1.8.11 not yet
> >>supported for use with netcdf-4.3.0
> >
> >It's definitely supported, and we've been doing our testing with
> >HDF5-1.8.11 since their
> >first pre-release.  I didn't notice the problem until I started doing
> >some parallel
> >testing, and I think it only occurs when linking with parallel
> >hdf5-1.8.11.
> >
> >I documented it here:
> >
> >  http://www.unidata.ucar.edu/netcdf/docs/build_parallel.html
> >
> >but I have never determined why "-ldl" is necessary.  It might be a good
> >question for
> >the HDF Group, so I'm CC:ing them on this response.
> >
> >--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: AJV-500600
Department: Support netCDF
Priority: Normal
Status: Closed