Re: [gentoo-dev] Portage FEATURE suggestion - limited-visibility builds

[Michael Mol]

On Tue, Jul 31, 2012 at 10:56 AM, Ian Stakenvicius <axs@g.o> wrote:
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> On 31/07/12 10:55 AM, Michael Mol wrote:
>> On Tue, Jul 31, 2012 at 10:48 AM, "Paweł Hajdan, Jr."
>> <phajdan.jr@g.o> wrote:
>>> On 7/26/12 8:26 PM, Rich Freeman wrote:
>>>> I've been messing around with namespaces and some of what
>>>> systemd has been doing with them, and I have an idea for a
>>>> portage feature.
>>>>
>>>> But before doing a brain dump of ideas, how useful would it be
>>>> to have a FEATURE for portage to do a limited-visibility build?
>>>> That is, the build would be run in an environment where the
>>>> root filesystem appears to contain everything in a DEPEND
>>>> (including @system currently) and nothing else?
>>>
>>> I was thinking about something similar too. In my opinion it's a
>>> great feature. If/when there are any bugs to get this
>>> implemented, please let me know.
>>>
>>> A possible alternative implementation would be to make the
>>> sandbox deny access to anything outside DEPEND. One totally crazy
>>> idea to make that fast are extended attributes (portage would
>>> record which package a file belongs to when merging the file).
>>> Another possible solution is using a cache.
>>
>> We already have the ability to run commands like 'equery b
>> $somefile' to map a file back to a package, so the data for a
>> filesystem helper should already be available in whatever database
>> equery is using.
>>
>
> Although that is true, it would be -WAY- too slow to generate said
> list via equery/q* helpers; I think that's where the
> extended-attributes and/or cache idea comes into play.

Yeah, I was thinking you could use the equery database to initially
fill the cache. Spawning an equery instance for every file access
would be absolute madness. I have enough entropy problems on my
system.

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:wq