AC_CHECK_LIB(pthread,pthread_create,,
[AC_MSG_ERROR([[Cannot find pthreads (try --with-context=ucontext if you haven't already tried).]])])
AC_DEFINE([CONTEXT_THREADS],1,[Define if xbt contexts are based on our threads implementation or not])
AC_CHECK_LIB(pthread,pthread_create,,
[AC_MSG_ERROR([[Cannot find pthreads (try --with-context=ucontext if you haven't already tried).]])])
AC_DEFINE([CONTEXT_THREADS],1,[Define if xbt contexts are based on our threads implementation or not])