Re: [gentoo-dev] Creating a USE_EXPAND for ssl providers

["Chí-Thanh Christopher Nguyễn" <chithanh@gentoo.org>]

Michał Górny schrieb:
>>
>> I don't like this. If the user specifies several SSL providers in
>> make.conf, it should mean that any of these is fine and the ebuild can
>> choose an arbitrary one. The exactly-one-of operator would cause emerge
>> to complain in this case and possibly force the user to have complex
>> package.use setups.
> Your idea comes with three significant drawbacks:
>
> 1. USE flag setups become unclear -- user sees five different SSL
> providers turned on and has no clue which one is actually used.

Does that really matter? What I got from bug 512664 comment 0 is the
desire to ensure that a certain crypto provider (in this case, openssl)
is *not* used.

> 2. You create 2^n-1 valid USE flag combinations which map to n
> different file sets. This means that there are 2^n-n-1 useless USE flag
> combination which make matching binary packages a PITA.

This is indeed a problem, if producer and consumer of the binpkg are different entities. It could be mitigated by pre-populating the default list of crypto providers so that most users will not need to change it.


> 3. There is no clean way of enforcing SSL provider match between
> packages. Wasn't this thread initially about curl and rtmpdump
> requiring matching flags?

It could be enforced if an eclass does the actual choice of crypto
provider in a reproducible way. That would be not trivial though.


Best regards,
Chí-Thanh Christopher Nguyễn