Post do_package tasks and rm_work

Recently I ran into an issue surrounding a task that we needed to have run after the do_package task because some of its side effects muddied the ${D} directory with files we didn't want to be in our ipk package. We created a task do_create_foo that did the work we needed and set it to run after do_package. To our surprise, the stamp for the task was never created and the task tried to run every a recipe that depended on this one ran. This was especially bad since we use the rm_work class to save disk space, so when do_create_foo was run again, the ${D} was often missing entirely.

Some very long digging later, we discovered that the rm_work class was actually removing the stamp because it wasn't in its hard coded list or in the SSTATETASKS list. Since we didn't want to mess with making the task into an sstate task, we pulled a copy of rm_work.bbclass into our layer and added *do_create_foo* to the case statement in do_rm_work. Your mileage may vary, but hopefully this helps anyone out there with the case of the missing stamp!

Populating sysroot from non-standard paths

Your recipe is finally installing all of the correct files into their correct places during do_install, they are being packaged up properly, but something is still wrong. None of these files are ending up in the sysroot so other packages can make use of them. What's going on?!?

OE-Core only knows about a handful of paths that it should transfer over to the sysroot. In order to teach it about others, you need to define a function that does the populating and then add it to SYSROOT_PREPROCESS_FUNCS. Here's an example for recipe foo:

foo_populate_sysroot() {
sysroot_stage_dir ${D}/my/custom/path ${SYSROOT_DESTDIR}/my/custom/path
}
SYSROOT_PREPROCESS_FUNCS += "foo_populate_sysroot"

This will cause /my/custom/path to be exported to the sysroot and be available for other recipes to use. That's it, you're done! Note that the name of the function can be anything, the above name was used just for clarity.