[yocto] is it "IMAGE_INSTALL +=" or "IMAGE_INSTALL_append ="?

[Paul Eggleton]

On Tuesday 19 June 2012 08:22:00 Robert P. J. Day wrote:
>   currently, the dev manual (Section 4.2.1) proposes the use of
> 
>   IMAGE_INSTALL += "strace"
> 
> but the poky ref manual in the variable glossary explicitly
> discourages that form, and instead recommends
> 
>   IMAGE_INSTALL_append = " package-name"
> 
>   can we agree that the "_append" form is preferred?  thoughts?

The reference manual is a little unclear on what "ordering issues" means. += 
works just fine, it's just that if you happen to use it at some point before 
core-image.bbclass line sets it with ?= (i.e. either in local.conf or before 
the "inherit core-image" line in your image recipe) the ?= line in core-
image.bbclass will do nothing and you'll end up with much less in the 
IMAGE_INSTALL list than you expected. If you use _append, you can have that 
anywhere you like and it will always work, with the caveat that if you forget 
to add a leading space in the value to be appended, things will break.

Note that the part of 4.2.1 in the dev manual you refer to is specifically 
talking about making a copy of an image recipe and putting the IMAGE_INSTALL 
+= at the end, which will always work and won't suffer from any leading space 
issues. I'm not sure what we should change to improve this...

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre