My code (a very small piece of code) uses boost:threads; It performs perfectly with the Debian Sarge version of boost,but segfaults with the version I installed myself (using bjam "-sTOOLS=gcc"). The Boost version I installed is: 1_33_1; Debian Sarge version is 1_32_06. I tried to runs the tests from inside the compiled 1_33_1 version: it works perfectly; but when I copy, say tennis.cpp, in an other directory, and compile and link it with version 1_33_1 (the one I compiled), it segfaults. I think it's only a question of compiler options. ->My options (which makes the program crash): -DBOOST_HAS_THREADS -DBOOST_HAS_PTHREADS -D_REENTRANT What is false? This works with Debian installed version. ->what are the options used by bjam when compiling the tests? I need a personnal version of boost (not the debian one) because I want to use the property tree library... yours t.d. -- Thierry Dumont. Institut Camille Jordan -- Mathematiques-- Univ. Lyon I,43 Bd du 11 Novembre 1918, 69622 - Villeurbanne Cedex - France. Thierry.Dumont@maply.univ-lyon1.fr web: http://maply.univ-lyon1.fr/~tdumont