I am attempting to set install location with a conditional rule as follows:<br><br>&nbsp;&nbsp;&nbsp; install dummy : $(include-tree)<br>&nbsp;&nbsp;&nbsp; : &lt;install-source-root&gt;.. &lt;conditional&gt;@hss.set-install-base ;<br><br><br>The rule hss.set-install-base adds a &lt;location&gt; property to the property list if not already added.&nbsp; This results in the following stack trace:<br><br>error: default build must be identical in all alternatives<br>error: main target is ../../../../HSS3.0/HSS_ALL/AFC/Source/dummy<br>error: with &lt;conditional&gt;@hss.set-install-base<br>error: differing from previous default build<br>/cygdrive/c/mse/proj/boost-build/build/targets.jam:453: in build-main-targets from module object(project-target)@89<br>/cygdrive/c/mse/proj/boost-build/build/targets.jam:268: in targets-to-build from module object(project-target)@89<br>/cygdrive/c/mse/proj/boost-build/build/targets.jam:250: in object(project-target)@89.generate from module
 object(project-target)@89<br>...<br><br>This worked until I merged in all the latest CVS source changes (I was behind a few months).&nbsp; Is the code getting requirements attributes mixed up with default-build attributes?<br><br>Thanks<br>Mark<br><br><br>