If the compiler command in CXX contains more than one word, e.g. "ccache
g++", line 256 in distutils/unixccompiler.py only picks the first word
as the linker and discards the rest:

                    linker[i] = self.compiler_cxx[i]

On Ubuntu 9.04 the values of the variables are:

(Pdb) print linker
['gcc', '-pthread', '-shared', '-Wl,-O1', '-Wl,-Bsymbolic-functions']
(Pdb) print self.compiler_cxx
['ccache', 'g++']
(Pdb)

This patch seems to solve the problem for me. I think it should also
work with the environment variable setting on OS X, but I haven't tested it.

Aren't CC and CXX variables just for compilers?

"""
CC
    Program for compiling C programs; default `cc'.
CXX
    Program for compiling C++ programs; default `g++'.
"""
http://www.gnu.org/software/make/manual/make.html#index-CXX-848

The linker is usually called via a compiler, which arranges for compiler
specific libraries to be included in the linking. See e.g. section 10.2
in the GNU Make manual:

Linking a single object file

n is made automatically from n.o by running the linker (usually called
ld) via the C compiler. The precise command used is `$(CC) $(LDFLAGS)
n.o $(LOADLIBES) $(LDLIBS)'.

Distutils is now deprecated (see PEP 632) and all tagged issues are being closed. From now until removal, only release blocking issues will be considered for distutils.

If this issue does not relate to distutils, please remove the component and reopen it. If you believe it still requires a fix, most likely the issue should be re-reported at https://github.com/pypa/setuptools