While running os-cillation's XFCE4 graphical installer, upon configuring libxfce4util, it fails, and the relevant part of the log file reads:

---
## Configuring libxfce4util
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for gawk... gawk
checking whether gmake sets $(MAKE)... yes
checking whether to enable maintainer-specific portions of Makefiles... no
checking for style of include used by gmake... GNU
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking dependency style of gcc... gcc3
checking how to run the C preprocessor... gcc -E
checking for egrep... grep -E
checking for AIX... no
checking for library containing strerror... none required
checking for ANSI C header files... yes
checking for sys/types.h... yes
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking minix/config.h usability... no
checking minix/config.h presence... no
checking for minix/config.h... no
checking for gcc... (cached) gcc
checking whether we are using the GNU C compiler... (cached) yes
checking whether gcc accepts -g... (cached) yes
checking for gcc option to accept ANSI C... (cached) none needed
checking dependency style of gcc... (cached) gcc3
checking for a BSD-compatible install... /usr/bin/install -c
checking build system type... i686-pc-linux-gnu
checking host system type... i686-pc-linux-gnu
checking for a sed that does not truncate output... /bin/sed
checking for ld used by gcc... /usr/bin/ld
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking for /usr/bin/ld option to reload object files... -r
checking for BSD-compatible nm... /usr/bin/nm -B
checking whether ln -s works... yes
checking how to recognise dependent libraries... pass_all
checking dlfcn.h usability... yes
checking dlfcn.h presence... yes
checking for dlfcn.h... yes
checking for g++... no
checking for c++... no
checking for gpp... no
checking for aCC... no
checking for CC... no
checking for cxx... no
checking for cc++... no
checking for cl... no
checking for FCC... no
checking for KCC... no
checking for RCC... no
checking for xlC_r... no
checking for xlC... no
checking whether we are using the GNU C++ compiler... no
checking whether g++ accepts -g... no
checking dependency style of g++... none
checking how to run the C++ preprocessor... /lib/cpp
configure: error: C++ preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details.
!! Failed to configure libxfce4util, see the errors above
!! for details on the problem.
---

Of course, I'm probably supposed to know this already , but what I need to correct this? For reference, I am using gcc 3.4.3. What am I missing for this installation, and where can I find it?

When you get errors like this, your best bet is to google the line that gave you a problem. In this case, "configure: error: C++ preprocessor "/lib/cpp" fails sanity check"

Googling that finds a zillion hits with the solution - mainly that you need g++ (gcc is the c compiler, g++ is the c++ compiler).

Ok, this is even more embarassing, but I can't find g++ for download, only gcc.

Where are you trying to download it from? Your distro might refer to it as gcc-g++.

See here for more help.

Good luck

I got these same errors, and spent a lot of time at the installer help forum and was never able to resolve them.

Then I realized that there are fedora rpms available from gnomefiles. Downloaded the tarball, unzipped it, did a "rpm -Fvh *.rpm" in the directory where they unzipped to, and had the new version is just a few minutes.