diff -rup boost-jam-3.1.18.orig/build.jam boost-jam-3.1.18/build.jam

--- boost-jam-3.1.18.orig/build.jam 2010-04-02 22:41:15.059100821 +0200

+++ boost-jam-3.1.18/build.jam  2010-04-02 23:35:18.563541541 +0200

@@ -204,7 +204,7 @@ toolset darwin cc :  "-o " : -D

 ## GCC 2.x, 3.x, 4.x

 toolset gcc gcc : "-o " : -D

     : -pedantic -fno-strict-aliasing

-    [ opt --release : [ opt --symbols : -g : -s ] -O3 ]

+    [ opt --release : [ opt --symbols : -g : -s ] $(CFLAGS) ]

     [ opt --debug : -g -O0 -fno-inline ]

     -I$(--python-include) -I$(--extra-include) -Wno-long-long

     : -L$(--python-lib[1]) -l$(--python-lib[2]) ;

diff -rup boost-jam-3.1.18.orig/build.sh boost-jam-3.1.18/build.sh

--- boost-jam-3.1.18.orig/build.sh  2010-04-02 22:41:15.038698714 +0200

+++ boost-jam-3.1.18/build.sh   2010-04-02 23:39:04.663101117 +0200

@@ -12,7 +12,7 @@ BOOST_JAM_TOOLSET=

 echo_run ()

 {

     echo "$@"

-    $@

+    eval "$@"

     r=$?

     if test $r -ne 0 ; then

         exit $r

@@ -290,5 +290,9 @@ if test -x "./bootstrap/jam0" ; then

     if test "${BJAM_UPDATE}" != "update" ; then

         echo_run ./bootstrap/jam0 -f build.jam --toolset=$BOOST_JAM_TOOLSET "--toolset-root=$BOOST_JAM_TOOLSET_ROOT" clean

     fi

-    echo_run ./bootstrap/jam0 -f build.jam --toolset=$BOOST_JAM_TOOLSET "--toolset-root=$BOOST_JAM_TOOLSET_ROOT" "$@"

+    if test -z "$BOOST_JAM_TOOLSET_ROOT"; then

+        echo_run ./bootstrap/jam0 -f build.jam --toolset=$BOOST_JAM_TOOLSET "$@"

+    else

+        echo_run ./bootstrap/jam0 -f build.jam --toolset=$BOOST_JAM_TOOLSET "--toolset-root=$BOOST_JAM_TOOLSET_ROOT" "$@"

+    fi

 fi

​