I'm using Boost.Test and Boost v1.55 to unit test an application on Windows/Linux/ESXi. The ESXi build is done on a CentOS 5.10 machine, this has been working well for the main application, but the Boost.Test binary hits an assert before running any tests: /tmp # ./MyTests Test setup error: system_error produced by: ::sigaltstack( 0, &sigstk ) != -1: Function not implemented The "Function not implemented" problem has been a recurring problem for me while making my application compatible with ESXi. My basic understanding is that ESXi implements a subset of glibc. I saw a similar issue here: http://comments.gmane.org/gmane.comp.lib.boost.testing/7782 I'm wondering how I can disable this assert and what the repercussions would be. Thanks