5.4.2 Platform-specific configuration notes

While Libtool tries to hide as many platform-specific features as possible, some have to be taken into account when configuring either the Libtool package or a libtoolized package.

• You currently need GNU make to build the Libtool package itself.
• On AIX there are two different styles of shared linking, one in which symbols are bound at link-time and one in which symbols are bound at runtime only, similar to ELF. In case of doubt use LDFLAGS=-Wl,-brtl for the latter style.
• On AIX, native tools are to be preferred over binutils; especially for C++ code, if using the AIX Toolbox GCC 4.0 and binutils, configure with AR=/usr/bin/ar LD=/usr/bin/ld NM='/usr/bin/nm -B'.
• On AIX, the /bin/sh is very slow due to its inefficient handling of here-documents. A modern shell is preferable:

            CONFIG_SHELL=/bin/bash; export $CONFIG_SHELL
            $CONFIG_SHELL ./configure [...]
  

• For C++ code with templates, it may be necessary to specify the way the compiler will generate the instantiations. For Portland pgCC version5, use CXX='pgCC --one_instantiation_per_object' and avoid parallel make.
• On Darwin, for C++ code with templates you need two level shared libraries. Libtool builds these by default if MACOSX_DEPLOYMENT_TARGET is set to 10.3 or later at configure time. See rdar://problem/4135857 for more information on this issue.
• The default shell on UNICOS 9, a ksh 88e variant, is too buggy to correctly execute the libtool script. Users are advised to install a modern shell such as GNU bash.
• Some HP-UX sed programs are horribly broken, and cannot handle libtool's requirements, so users may report unusual problems. There is no workaround except to install a working sed (such as GNU sed) on these systems.
• The vendor-distributed NCR MP-RAS cc programs emits copyright on standard error that confuse tests on size of conftest.err. The workaround is to specify CC when run configure with CC='cc -Hnocopyr'.
• Any earlier DG/UX system with ELF executables, such as R3.10 or R4.10, is also likely to work, but hasn't been explicitly tested.
• On Reliant Unix libtool has only been tested with the Siemens C-compiler and an old version of gcc provided by Marco Walther.
• libtool.m4, ltdl.m4 and the configure.ac files are marked to use autoconf-mode, which is distributed with GNU Emacs 21, Autoconf itself, and all recent releases of XEmacs.
• When building on some linux systems for multilib targets libtool sometimes guesses the wrong paths that the linker and dynamic linker search by default. If this occurs, you may override libtool's guesses at configure time by setting the autoconf cache variables lt_cv_sys_lib_search_path_spec and lt_cv_sys_lib_dlsearch_path_spec respectively to the correct search paths.