On Tue, 4 May 2021, Quentin Schulz wrote:

Hi Robert,

On Tue, Apr 27, 2021 at 08:41:25AM -0400, Robert P. J. Day wrote:

for the first time, i'm digging around in the docs for how to
properly license various types of recipes, so a couple simple
questions to start with, at least so i can make a first pass of
cleaning up some content in front of me.

as we established recently, packagegroup files need no
licensing, the obvious observation being that they represent the
collection of licenses that comprise them. however, i notice that
the packagegroup.bbclass file does indeed define a default
license:

LICENSE ?= "MIT"

so not only does a packagegroup have a default (MIT) license, but
it's conditional suggesting one could give it a different license.
what other licenses would make sense for a packagegroup? I'm
sticking with the default that packagegroup recipe files need no
LICENSE assignment, but now i'm curious as to what other options
there are (or perhaps that that default assignment in
packagegroup.bbclass is obsolete).

Wild guess: all packages need a license. MIT is quite permissive so
safe as a default?

superficially makes sense, except that a packagegroup does not
really define a "package". perhaps all *recipe* files need a license
but, again, it's not clear how a packagegroup license should percolate
down to the packages it contains. or how things would percolate up.

suddenly, i want some coffee.

the same sort of question can be asked about image files,
including the generic OE core-image*.bb recipe files. of all those
current core-image files:

core-image-base.bb
core-image-minimal.bb
core-image-minimal-dev.bb
core-image-minimal-initramfs.bb
core-image-minimal-mtdutils.bb
core-image-tiny-initramfs.bb

fail into two camps.

the first sets a license, then inherits core-image:

LICENSE = "MIT"
inherit core-image

the second type simply "require"s one of the other recipe files so it
has no need to set its own license, as in core-image-minimal-dev.bb:

require core-image-minimal.bb

similar to packagegroups, does a core-image recipe really need a
separate LICENSE setting, or could that be added to core-image.bbclass
to centralize it (if it's even needed at all)?

Don't know about this one but I guess it's some rest of the original
implementation where I guess everything needed a LICENSE?

I can only guess, but maybe this'll start a discussion :)

finally, WRT .bbappend files, the original recipes will have
their own licenses and if the .bbappend file is doing nothing but
adding some configuration (you know, PACKAGECONFIG, EXTRA_OEMAKE,
that sort of thing), then there should be no need for licensing in
the bbappend file. does all this sound reasonable so far?

I wouldn't expect any bbappend to modify a package/recipe license
without changing the sources (version bump). But not much experience
with that, so might be a valid use case?

i'm not *trying* to be overly pedantic (well, yeah, i am :-), but
given the importance of licensing these days, i want to understand how
they work far more than i do at the moment, especially since my new
co-workers are asking me about them.

rday