Because --pre-clean is much, much slower if you've already built things. If things aren't rebuilding properly when switching between distros that's likely a bug in rosbuild, and you should file a ticket. Josh On Wed, Jul 14, 2010 at 11:57 AM, Dan Lazewatsky wrote: > I've noticed similar confusion from less experienced folks about when > to clean. Is there a reason that rosmake doesn't run make clean by > default? We're going to be setting up one of our computer labs with > ROS for the fall semester, and I'm wondering if I should alias rosmake > to rosmake --pre-clean to avoid the inevitable slew of emails from > frantic students. > > -Dan > On Jul 14, 2010, at 12:54 PM, Jack O'Quin wrote: > > > On Mon, Jul 12, 2010 at 7:40 PM, Ken Conley > > wrote: > >> More information here: > >> > >> http://www.ros.org/news/2010/07/ros-c-turtle-alpha-5-released.html > >> > >> -- your friendly neighborhood ROS C Turtle team > > > > We have been upgrading many of our students from boxturtle to cturtle. > > The binary installs seem to work fine. But several students stumbled > > over problems of binary incompatibility for external packages built > > with the two releases. > > > > After installing the cturtle packages, they update $ROS_PACKAGE_PATH > > and try to run their code. It generally segfaults, and they don't know > > what to do (these are smart, but relatively inexperienced > > undergraduates). > > > > Even running rosmake again does not work. Apparently, the build > > subtree is full of incompatible files. So, they need to at least use > > the rosmake --pre-clean option. I've been recommending that they check > > out a whole new tree and build that. > > > > So, this is not a big deal, but I was surprised how much confusion it > > created. It should probably be documented somehow in the release > > notes. > > > > If it were possible for rosmake and rosrun to detect packages built > > with the old ABI and issue a clear warning, that would help a lot. > > Even better if rosmake could automatically do the right thing (e.g. > > "make clean && make"). > > > > I consider this more of a documentation issue than a defect, but > > probably many more users will stumble over it soon. > > -- > > joq > > _______________________________________________ > > ros-users mailing list > > ros-users@code.ros.org > > https://code.ros.org/mailman/listinfo/ros-users > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users >