[OE-core] Ensuring a task is re-ran when local.conf is updated

[Richard Purdie]

On Fri, 2014-05-02 at 22:51 +0100, Paul Barker wrote:
> On 2 May 2014 22:34, Richard Purdie <richard.purdie at linuxfoundation.org> wrote:
> > On Fri, 2014-05-02 at 17:43 +0100, Paul Barker wrote:
> >>
> >> Am I missing something here? Is it expected that this variable change
> >> is detected and the relevant tasks re-executed? I know changing
> >> variables like PREFERRED_PROVIDER_* in local.conf causes things to be
> >> rebuilt, so why does that work and this not?
> >
> > This should work, I'm not sure why it wouldn't. The code should be able
> > to detect the dependency on the IPK_HIERARCHICAL_FEED variable and
> > notice when the value changes.
> >
> > I'd have to experiment with some builds to figure out anything further
> > but its probably worth opening a bug report as it sounds broken.
> >
> > bitbake-dffsigs on a siginfo file of a do_package_write_ipk is where to
> > start with debugging, it should show the dependency on the variable.
> 
> Looks like I found the issue quickly using bitbake-diffsigs.
> do_package_write_ipk does:
>     localdata = bb.data.createCopy(d)
> Then uses localdata.
> 
> If I check localdata.getVar(), the variable name doesn't appear in the
> list of dependencies.
> 
> If instead I check d.getVar(), it does appear in the list of dependencies.
> 
> It looks like localdata is used so that certain variables can be set
> without the changes affecting anything else (PKG, OVERRIDES, ROOT,
> etc). But there are also some calls to localdata.getVar() for
> PACKAGE_ARCH and ALLOW_EMPTY.
> 
> With my check changed to d.getVar(), the dependencies are: (['PKGE',
> 'IPK_HIERARCHICAL_FEED', 'get_package_additional_metadata',
> 'PKGWRITEDIRIPK', 'OPKGBUILDCMD', 'mapping_rename_hook', 'PKGDEST',
> 'PACKAGES', 'HOMEPAGE'])
> 
> Does this mean changes to PACKAGE_ARCH and ALLOW_EMPTY may go unnoticed?

It may well do and I've realised the issue:

codeparser.py:
class PythonParser():
    getvars = ("d.getVar", "bb.data.getVar", "data.getVar", "d.appendVar", "d.prependVar")

we probably need to change this to an .endswith(".getVar", ".appendVar",
".prependVar") type check...

Cheers,

Richard