How to specify dependencies with "foo_msgs" catkin packages

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I believe the modern way of doing this is to add a dependency on ${catkin_EXPORTED_TARGETS}, as specified on this documentation page. It should look something like this:

find_package(catkin REQUIRED COMPONENTS foo_msgs)

add_dependencies(your_program ${catkin_EXPORTED_TARGETS})
add_dependencies(your_library ${catkin_EXPORTED_TARGETS})

catkin_make with an argument just passes that argument to make. That a make target for the package exists is more by chance than design, I'd guess it is added by cmake for each subfolder (but not with nested folders). Maybe you can open a ticket on github to add the feature of a dedicated target to make. However a small problem exists, frequently a package named foo defines an executable named foo, so the target names overlap each other. Not sure whether any clean solution is possible. At least it wont be straightforward.

What you can do to cause "make foo_msgs" not be a noop is in package foo_msg, add a dependency like this:

add_custom_target(${PROJECT_NAME} DEPENDS ${PROJECT_NAME}_gencpp)

which is equivalent to

# add_custom_target(foo_msgs DEPENDS foo_msgs_gencpp)

but easier for copy&paste

[Update3: this is wrong:

Update: add_dependencies is definitely the wrong way to go, the way you use it (in foo, add dependency to foomsg). add_dependency should never cross catkin project boundaries. For you it only works coincidentally (because catkin cheats cmake conventions), it will break build in other cases or when building the projects in isolation.]

Update3: So it seems that indeed currently, calling add_dependencies accross package boundaries it currently the only recommendable way to achieve that the headers generated by foo_msg exist before they are being consumed by a target in foo.

We'll discuss this in the buildsystem SIG and maybe there will be a cleaner solution in the future.Discussion here: https://groups.google.com/d/topic/ros-sig-buildsystem/dvVO5QCHBLM/discussion

As the other answers already state, you need to add the correct dependencies in the CMakeLists.txt. However, I found I also have to correctly specify the dependencies in the package.xml, otherwise the packages would not build in the correct order (i.e., first foo_msgs then foo).

I am using the catkin tools for building. Not sure if it is strictly necessary for caktin_make.

A minimal package.xml could look like this:

<?xml version="1.0"?>
<package format="2">
  <name>foo</name>
  <version>1.0.0</version>
  <description>Package foo depends on foo_msgs</description>
  <maintainer email="foo@bar.com">Foo Bar<maintainer>
  <license>Foo Bar</license>
  <buildtool_depend>catkin</buildtool_depend>
  <depend>roscpp</depend>
  <depend>foo_msgs</depend>
</package>