I confirmed this problem on my system.<br>  <br>  lib : : &lt;conditional&gt;@sources ;<br>  <br>  when "bjamed" does nothing other than indicate nnn targets found.&nbsp; Change this to:<br>  <br>  exe : : &lt;conditional&gt;@sources ;<br>  <br>  causes the sources returned by [ sources ] to be compiled.<br>  <br>  Anyone have a fix?&nbsp;&nbsp; I was hoping to exploit this feature.<br>  <br>  Regards,<br>  Mark<br><br><b><i>Jaroslav Gresula &lt;jgresula@seznam.cz&gt;</i></b> wrote:<blockquote class="replbq" style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><build><source><variant><source><variant><source><build><conditional>It seems to me that the <source> feature does not work for lib targets. <br></source></conditional></build></source></variant></source></variant></source></build></blockquote><br>