[yocto] confusion about DEPENDS vs RDEPENDS

[Hans Beckérus]

Hi, I am a little bit confused about how to handle these two and what
they are supposed to solve. I have so far never used RDEPENDS but only
DEPENDS.
But I am also having severe problems when building a rootfs image when
one of my user space libraries are changed from eg. libfoo.so.1 to
libfoo.so.3. Even though all my packages that have dependencies to it
includes it in a DEPENDS.
The error I get during rootfs build is:

| Computing transaction...error: Can't install
someapp-1.0-r0 at cortexa9_vfp: no package provides libfoo.so.1

But there is no libfoo.so.1 in my sysroot, it has been replaced by libfoo.so.3.
I know for sure that 'someapp' was rebuilt, but still I got the error message.
What do seem to help is to force a fetch of 'someapp' and then rebuild
which sort of indicates that some garbage was left behind. But having
a package listed in DEPENDS will not force a new fetch if I am not
mistaken.

Have I been using the DEPENDS variable incorrectly? Would it make a
difference if I used RDEPENDS instead?

Thanks.
Hans