Due to running libtoolize --force --copy by default in spec file libtool
files supplied with pspell are replaced with those currently installed in
the system that are not compatible with libtool packaged in with pspell. As
a result, shared libraries being built aren't linked against libstdc++.so
and consequently are unusable. The problem disappeared after I've added
'%define __libtoolize /bin/true' line into the spec file just before
%configure macro call.