Execute something as part of local_setup.bash call

[BrannonKing]

With the present build system (ament), is there a way for me to specify some code that might get ran with the setup scripts? I just need to add some additional environment variables at the moment. In other words, I want to add a new package to my repos file that needs no real compile but simply adds additional environment variables set when sourcing in local_setup.bash.

[Paul_Bovbel]

You’re looking for the ament_environment_hooks macro, which is similar to catkin’s catkin_add_env_hooks:

ament/ament_cmake/blob/master/ament_cmake_core/cmake/environment_hooks/ament_environment_hooks.cmake

[dirk-thomas]

An example usage could be the .sh / .bat files the opensplice_cmake_module package uses to set e.g. OSPL_HOME.

[BrannonKing]

This approach will work just fine for me. Thanks guys.

[BrannonKing]

One follow-up question: are environment variables exported through the ament_environment_hooks mechanism exported and available for dependent builds to utilize as part of a long build chain? Or are they only set when explicitly sourcing in the setup script files?

[wjwwood]

They are available at build time and run time. There is an open issue to have the option to have a separate build and run time set of hooks:

https://github.com/ament/ament_tools/issues/76

[BrannonKing]

They are available at build time…

To clarify one thing in that regard: it appears that data provided through environment hooks are available at build time only to packages explicitly specifying a build dependency in their package.xml upon the hook provider package.

[wjwwood]

@BrannonKing

To clarify one thing in that regard: it appears that data provided through environment hooks are available at build time only to packages explicitly specifying a build dependency in their package.xml upon the hook provider package.

Yes, that’s intentional. It also happens transitively, so if A defines a hook, B depends on A, and C depends on just B, then C will still see the side effect of the hook in A despite not directly depending on A.

[BrannonKing]

I wasn’t seeing the transitive behavior in my testing. I had expected that, but I don’t think it works at the moment.

[dirk-thomas]

In the environment used to build a package the following packages are being sourced before: the direct build dependencies and of those all recursive build | build_export | buildtool_export | exec dependencies.

A package specific local_setup file from the install space will source the following packages: all direct run and test dependencies are being sourced.

[BrannonKing]

Thanks. Adding a build_export node on my intermediate package appears to fix the issue I was seeing.