[yocto] Question / issue

[Paul McGougan]

From: Bruce Ashfield [mailto:bruce.ashfield at windriver.com] 
 
> > Secondly, (and this is our main issue) I have found that by adding the 
> > do_install_append function, even if it is completely empty, whenever I 
> > try to bitbake anything that depends on the kernel, that bitbake always 
> > re-runs the kernel install stage, even when there have been no changes. 
> > Literally I can run a bitbake, then run the same bitbake command again, 
> > and both times the kernel install stage gets run (this is a problem 
> > because it takes a long time to run). It appears to be happening because 
> > the stampfile is not found every time (the hash appears to be wrong). 
> > Is this a bug? Is there a fix or work-around for this problem?

> In this front, I'm not the best reference. Checking the sstate signature
> might help, it should show which variables are being used .. and possibly
> invalidating the signature, triggering the steps to run again.

Thanks Bruce.

Just for reference of anyone else who runs into a similar issue our issue was:
1. The do_install_append function was not *really* empty, the content of it 
was commented out.
2. The dependency parser when parsing recipes not only looks for content
changes, but for also for changes to the values of referenced variables, and
unfortunately it still performs variable-value substitution in commented-out
code. In our case, we had the variable $DATETIME in there (but commented
out), this caused the dependency checker to substitute in the current value for
DATETIME which of course changed on each run.

The fix was to add:
do_install[vardepsexclude] += "DATETIME"

Regards,
Paul McGougan

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