-test -e $INSTALL_ROOT/bin/sbcl && \
- cp $INSTALL_ROOT/bin/sbcl $INSTALL_ROOT/bin/sbcl.old
-test -e $SBCL_HOME/sbcl.core && \
- cp $SBCL_HOME/sbcl.core $SBCL_HOME/sbcl.core.old
+# move old versions out of the way. Safer than copying: don't want to
+# break any running instances that have these files mapped
+test -f $INSTALL_ROOT/bin/sbcl && \
+ mv $INSTALL_ROOT/bin/sbcl $INSTALL_ROOT/bin/sbcl.old
+test -f $SBCL_HOME/sbcl.core && \
+ mv $SBCL_HOME/sbcl.core $SBCL_HOME/sbcl.core.old