Re: [gentoo-pms] IUSE_EFFECTIVE and IUSE_REFERENCEABLE

[Ulrich Mueller]

>>>>> On Wed, 18 Jun 2014, Ciaran McCreesh wrote:

> The spec is correct, and discusses what you can actually rely upon
> working. It is unfortunate that the Council introduced this
> confusion by approving "what Portage has implemented" for EAPI 4,
> without considering the implications of approving (+) and (-)
> without the stricter USE rules.

Maybe it becomes clearer if we imagine for the moment that there never
was an EAPI 4.

Take an EAPI 5 ebuild for cat/foo-1 that defines the following
dependency:

   RDEPEND="cat/bar-1[abi_x86_64(-)]"

ABI_X86 is in USE_EXPAND of the profile, also abi_x86_64 is forced
enabled via the profile's use.force.

cat/bar-1 is EAPI 2 and has an empty IUSE.

Now, according to the spec:
| For EAPIs listed in table 5.2 as not supporting profile defined IUSE
| injection, IUSE_REFERENCEABLE is equal to the calculated IUSE value.

So in EAPI 2, IUSE_REFERENCEABLE is equal to IUSE, therefore for bar-1
it should be empty.

Furthermore:
| In a 4-style use dependency, the flag name may immediately be
| followed by a default specified by either (+) or (-). The former
| indicates that, when applying the use dependency to a package that
| does not have the flag in question in IUSE_REFERENCEABLE, the
| package manager shall behave as if the flag were present and
| enabled; the latter, present and disabled. 

In the above RDEPEND, we have a default (-) specifier, and the flag is
not in IUSE_REFERENCEABLE of bar-1. So the PM should behave as if the
flag was disabled, and the dependency should not be matched.

However, what we observe is that the PM behaves as if abi_x86_64 was
in IUSE_REFERENCEABLE, so the dependency _is_ matched.

What am I missing here?

Ulrich