Dynamically loading shared objects compiled from Fortran may fail with an
undefined symbol message.  The symbol string returned by dlerror is garbage
and this sometimes leads to a segmentation fault.

This problem has been reported on the mailing lists of the R language
(http://www.r-project.org). R has a facility for users to create
dynamically loaded "packages" to extend the functionality of the language.
Many of these packages contain Fortran code.

The problem is specific to Red Hat 6.2 and has not been reproduced on other
platforms.  It only occurs with packages that contain Fortran code.

Here is an example, which is reproducible.  You can download an RPM
of R from
http://www.r-project.org/bin/linux/redhat/6.x/i386/R-base-1.1.0-2.i386.rpm
The source for the tseries package can be downloaded from
http://www.r-project.org/src/contrib/tseries_0.5-2.tar.gz
To install the tseries package, type (as root)
R CMD INSTALL tseries_0.5-2.tar.gz
The launch R within gdb by typing "R -d gdb" and at the R prompt type
"library(tseries)" to load the tseries package


Here is a stack trace:

$ R -d gdb
...
(gdb) set args --vanilla
(gdb) r
Starting program: /usr/lib/R/bin/R.bin --vanilla
...
> library(tseries)

Program received signal SIGSEGV, Segmentation fault.
_dl_lookup_symbol (undef_name=0x81f52f60 <Address 0x81f52f60 out of
bounds>, 
    ref=0xbfffaae0, symbol_scope=0x81edab4, 
    reference_name=0x81ea018 "/home/martyn/Rlibs/tseries/libs/tseries.so", 
    reloc_type=18) at ../sysdeps/generic/dl-hash.h:31
31	../sysdeps/generic/dl-hash.h: No such file or directory.
(gdb) bt
#0  _dl_lookup_symbol (
    undef_name=0x81f52f60 <Address 0x81f52f60 out of bounds>,
ref=0xbfffaae0, 
    symbol_scope=0x81edab4, 
    reference_name=0x81ea018 "/home/martyn/Rlibs/tseries/libs/tseries.so", 
    reloc_type=18) at ../sysdeps/generic/dl-hash.h:31
#1  0x400096ad in _dl_relocate_object (l=0x81ed8b0, scope=0x81edab4,
lazy=0, 
    consider_profiling=0) at ../sysdeps/i386/dl-machine.h:326
#2  0x40191be4 in dl_open_worker (a=0xbfffac4c) at dl-open.c:182
#3  0x4000ac3b in _dl_catch_error (errstring=0xbfffac48, 
    operate=0x40191990 <dl_open_worker>, args=0xbfffac4c) at dl-error.c:141
#4  0x40191d3d in _dl_open (
    file=0xbfffbdec "/home/martyn/Rlibs/tseries/libs/tseries.so", mode=2, 
    caller=0xbfffac48) at dl-open.c:232
#5  0x400503d3 in dlopen_doit (a=0xbfffad5c) at dlopen.c:41
#6  0x4000ac3b in _dl_catch_error (errstring=0x40052080, 
    operate=0x400503a8 <dlopen_doit>, args=0xbfffad5c) at dl-error.c:141
#7  0x400508b9 in _dlerror_run (operate=0x400503a8 <dlopen_doit>, 
    args=0xbfffad5c) at dlerror.c:125

#8  0x40050393 in __dlopen_check (
    file=0xbfffbdec "/home/martyn/Rlibs/tseries/libs/tseries.so", mode=2)
    at dlopen.c:53
#9  0x80e4b3a in AddDLL (
    path=0xbfffbdec "/home/martyn/Rlibs/tseries/libs/tseries.so",
    asLocal=1, now=1) at dynload.c:207