Re: erroneous behavior in 2-style USE dependencies?

On Tue, 2020-06-16 at 23:07 +0000, Michael Lienhardt wrote:
> Dear all,
> 
> My bad for not noticing it sooner, but when there is a dependency like ">=sys-fs/udev-208-r1:0/0[static-libs?]" (that occurs in virtual/libgudev-215-r3),
>  since 'static-libs' is not a use flags of sys-fs/udev-242, that cpv is silently not considered during dependency solving by emerge.
> However, the PMS states:
>  - it is an error for a use dependency to be applied to an ebuild which does not have the flag in question in IUSE_REFERENCEABLE
> 

This is a bit like undefined behavior.  PMS says such a thing shouldn't
happen (i.e. the ebuild is wrong) but does not force specific error
handling.  You could reject the ebuild entirely or reject dependencies
that don't have the flag in question (even if it's disabled).  You could
also pretend it's 'static-libs(-)?' but that would be bad if the default
was supposed to be '(+)'.

> This is related to the tool I'm working on: should my tool allow this behavior, or fail like it is currently doing (I guess the former)?
> 

That depends on what the tool is doing.  I suppose you probably don't
need very strict behavior there.

-- 
Best regards,
Michał Górny

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