During the installation of calibre, I got this error:
* Building of dev-python/cssselect-0.7.1 with CPython 3.2... python3.2 setup.py build -b build-3.2 running build running build_py creating build-3.2 creating build-3.2/lib creating build-3.2/lib/cssselect copying cssselect/parser.py -> build-3.2/lib/cssselect copying cssselect/xpath.py -> build-3.2/lib/cssselect copying cssselect/tests.py -> build-3.2/lib/cssselect copying cssselect/__init__.py -> build-3.2/lib/cssselect warning: build_py: byte-compiling is disabled, skipping. usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...] or: setup.py --help [cmd1 cmd2 ...] or: setup.py --help-commands or: setup.py cmd --help error: invalid command 'build_sphinx' * ERROR: dev-python/cssselect-0.7.1 failed (compile phase): * (no error message) * * Call stack: * ebuild.sh, line 93: Called src_compile * environment, line 3663: Called die * The specific snippet of code: * "$(PYTHON -f)" setup.py build_sphinx || die; * * If you need support, post the output of `emerge --info '=dev-python/cssselect-0.7.1'`, * the complete build log and the output of `emerge -pqv '=dev-python/cssselect-0.7.1'`. * The complete build log is located at '/var/tmp/portage/dev-python/cssselect-0.7.1/temp/build.log'. * The ebuild environment file is located at '/var/tmp/portage/dev-python/cssselect-0.7.1/temp/environment'. * Working directory: '/var/tmp/portage/dev-python/cssselect-0.7.1/work/cssselect-0.7.1' * S: '/var/tmp/portage/dev-python/cssselect-0.7.1/work/cssselect-0.7.1'
Of course, the simple solution is to disable the doc use flag. If you just want the software, stick to this solution.
Further tries lead to the interesting fact, that setup.py is working with python 2.7 only.
tunix ~ # cd /var/tmp/portage/dev-python/cssselect-0.7.1/work/cssselect-0.7.1 tunix cssselect-0.7.1 # python3.2 setup.py build_sphinx usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...] or: setup.py --help [cmd1 cmd2 ...] or: setup.py --help-commands or: setup.py cmd --help error: invalid command 'build_sphinx' tunix cssselect-0.7.1 # python2.7 setup.py build_sphinx running build_sphinx Running Sphinx v1.0.7 loading pickled environment... done building [html]: targets for 0 source files that are out of date updating environment: 0 added, 0 changed, 0 removed looking for now-outdated files... none found no targets are out of date.
(If you issue the commands for the first time, the last output will be slightly different.)
Although python 2.7 is the default, portage still uses both versions to build the documentation.
tunix ~ # eselect python list Available Python interpreters:  python2.7 *  python3.1  python3.2
As the default setup.py fails for python 3.x, we have to disable python 3.x temporarily. I discourage using /etc/make.conf for USE_PORTAGE, as you only want to emerge one package without support for python3.2. Therefore, this is the workaround:
tunix ~ # USE_PYTHON="2.7" emerge --oneshot cssselect
As I mentioned before, cssselect was a dependency of calibre. The –oneshot flag does not add the package to the world-file, hence, you should only use this flag if you get this error while portage is installing a dependency.