I use up-to-date Debian testing (wheezy), amd64 architecture. I have made a "clone" of the developmental version of Python 3.3. "make -s -j3" prints: ==== ... Python build finished, but the necessary bits to build these modules were not found: _bz2 _curses _curses_panel _dbm _gdbm _lzma _sqlite3 _ssl readline zlib To find the necessary bits, look in setup.py in detect_modules() for the module's name. Failed to build these modules: _crypt nis [101752 refs] ==== I looked into bz2. My system already contained the Debian packages libbz2-dev, libbz2-1.0, and bzip2. From the Debian website, I got the list of all the files in these three packages: ==== Filelist of package libbz2-dev in wheezy of architecture amd64 /usr/include/bzlib.h /usr/lib/x86_64-linux-gnu/libbz2.a /usr/lib/x86_64-linux-gnu/libbz2.so /usr/share/doc/libbz2-dev ==== Filelist of package libbz2-1.0 in wheezy of architecture amd64 /lib/x86_64-linux-gnu/libbz2.so.1 /lib/x86_64-linux-gnu/libbz2.so.1.0 /lib/x86_64-linux-gnu/libbz2.so.1.0.4 /usr/share/doc/libbz2-1.0/changelog.Debian.gz /usr/share/doc/libbz2-1.0/changelog.gz /usr/share/doc/libbz2-1.0/copyright ==== Filelist of package bzip2 in wheezy of architecture amd64 /bin/bunzip2 /bin/bzcat /bin/bzcmp /bin/bzdiff /bin/bzegrep /bin/bzexe /bin/bzfgrep /bin/bzgrep /bin/bzip2 /bin/bzip2recover /bin/bzless /bin/bzmore /usr/share/doc/bzip2/changelog.Debian.gz /usr/share/doc/bzip2/changelog.gz /usr/share/doc/bzip2/copyright /usr/share/man/man1/bunzip2.1.gz /usr/share/man/man1/bzcat.1.gz /usr/share/man/man1/bzcmp.1.gz /usr/share/man/man1/bzdiff.1.gz /usr/share/man/man1/bzegrep.1.gz /usr/share/man/man1/bzexe.1.gz /usr/share/man/man1/bzfgrep.1.gz /usr/share/man/man1/bzgrep.1.gz /usr/share/man/man1/bzip2.1.gz /usr/share/man/man1/bzip2recover.1.gz /usr/share/man/man1/bzless.1.gz /usr/share/man/man1/bzmore.1.gz ==== What is the problem? Does wheezy amd64 put files in unusual places?