Symlink stage may fail when binary files collide

System Info

• Operating System: ubuntu 14.04.5
• Python Version: 2.7.6
• Version of catkin_tools: 0.4.4
• ROS Distro: indigo

Build / Run Issue

• Works with catkin_make
• Works with catkin_make_isolated --merge
• Works with catkin build
• Works with catkin build -p1

Expected Behavior

catkin tools should emit a warning when a binary path needs to be symlinked from two different locations.

Actual Behavior

In the symlink stage, the code that checks if a symlink already exists will take an MD5 hash of colliding files. In the process of reading the file, it decodes the file and throws an exception the first time in encounters a non-ascii byte sequence. Here’s an example stacktrace.

Steps to Reproduce the Issue

Inspect this piece of code. Create two packages that produce a .so with the same name, then run catkin build.

[mantkiew]

I hit this issue recently and spent many hours trying to solve it. Finally, finding this issue, I commented out a fragment of CMakeFiles for an executable target that had the same name as an executable from another package we had, which solved the issue.

add_executable(interpolation
...omitted...
)

(there was the same executable target called “interpolation” in another package).

Catkin should definitely issue a warning about duplicate executable files.

[mantkiew]

I think these issues happen when you have targets with the same name from different packages which end up in the same location. I cannot give the specific CMakeFile as it’s internal but the tools should just double check that no target name conflicts arise.