[gentoo-dev] virtualx eclass

[gentoo-dev] virtualx eclass

[Doug Goldstein]

While the rule of thumb has been if an eclass needs something it should
provide it's own depends. However the virtualx eclass needs to be
different simply because in some cases it's only uses for tests (this is
it's most common usage in the whole) tree. When it's used for tests
pulling in the xorg-server the most ideal situation would be if
xorg-server was only pulled in on USE=test because currently for anyone
emerging an app that uses GTK+ they have a weird situation in the fact
that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
most usages of the X USE flag), however GTK+ itself due to it's usage of
the virtualx eclass pulls in xorg-server when USE=X, which is only used
for tests. This results in a confusing experience for users looking to
built a headless machine.

It'd be a lot more consistent if ebuilds provided a USE flag or directly
depended on the xorg-server and then used the functions in the eclass.
So in summary, those are the changes I plan on making very shortly. If
someone's got some input, please speak up.

--
Doug Goldstein

[gentoo-dev] Re: virtualx eclass

[Diego 'Flameeyes' Pettenò]

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Doug Goldstein <cardoe@gentoo.org> writes:

> It'd be a lot more consistent if ebuilds provided a USE flag or directly
> depended on the xorg-server and then used the functions in the eclass.
> So in summary, those are the changes I plan on making very shortly. If
> someone's got some input, please speak up.

Kinda like good ol' kde.eclass:

VIRTUALX_ONLY_TEST="yes"

inherit virtualx

and instead of using IUSE=X for that, IUSE=test.

-- 
Diego "Flameeyes" Pettenò
http://blog.flameeyes.eu/

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Re: [gentoo-dev] Re: virtualx eclass

[Doug Goldstein]

Diego 'Flameeyes' Pettenò wrote:
> Doug Goldstein <cardoe@gentoo.org> writes:
>
>   
>> It'd be a lot more consistent if ebuilds provided a USE flag or directly
>> depended on the xorg-server and then used the functions in the eclass.
>> So in summary, those are the changes I plan on making very shortly. If
>> someone's got some input, please speak up.
>>     
>
> Kinda like good ol' kde.eclass:
>
> VIRTUALX_ONLY_TEST="yes"
>
> inherit virtualx
>
> and instead of using IUSE=X for that, IUSE=test.
>
>   
That leaves a conditional that must be evaluated in the global scope
every time the depends are looked at.

And if that isn't set then making xorg-server always required in DEPEND?

What about packages that rely on virtualx to depend on xorg-server for
them (i.e. a RDEPEND)?

Re: [gentoo-dev] Re: virtualx eclass

[Doug Goldstein]

Doug Goldstein wrote:
> Diego 'Flameeyes' Pettenò wrote:
>   
>> Doug Goldstein <cardoe@gentoo.org> writes:
>>
>>   
>>     
>>> It'd be a lot more consistent if ebuilds provided a USE flag or directly
>>> depended on the xorg-server and then used the functions in the eclass.
>>> So in summary, those are the changes I plan on making very shortly. If
>>> someone's got some input, please speak up.
>>>     
>>>       
>> Kinda like good ol' kde.eclass:
>>
>> VIRTUALX_ONLY_TEST="yes"
>>
>> inherit virtualx
>>
>> and instead of using IUSE=X for that, IUSE=test.
>>
>>   
>>     
> That leaves a conditional that must be evaluated in the global scope
> every time the depends are looked at.
>
> And if that isn't set then making xorg-server always required in DEPEND?
>
> What about packages that rely on virtualx to depend on xorg-server for
> them (i.e. a RDEPEND)?
>
>   
For the third line item, those packages are broken in general and need
to be fixed so that's out of the scope of this.

Re: [gentoo-dev] virtualx eclass

[Doug Goldstein]

Doug Goldstein wrote:
> While the rule of thumb has been if an eclass needs something it should
> provide it's own depends. However the virtualx eclass needs to be
> different simply because in some cases it's only uses for tests (this is
> it's most common usage in the whole) tree. When it's used for tests
> pulling in the xorg-server the most ideal situation would be if
> xorg-server was only pulled in on USE=test because currently for anyone
> emerging an app that uses GTK+ they have a weird situation in the fact
> that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
> most usages of the X USE flag), however GTK+ itself due to it's usage of
> the virtualx eclass pulls in xorg-server when USE=X, which is only used
> for tests. This results in a confusing experience for users looking to
> built a headless machine.
>
> It'd be a lot more consistent if ebuilds provided a USE flag or directly
> depended on the xorg-server and then used the functions in the eclass.
> So in summary, those are the changes I plan on making very shortly. If
> someone's got some input, please speak up.
>
>   
Dave Leverton brings up a better suggestion. Providing VIRTUALX_DEPS and
having the ebuild just toss that into it's depends as needed.

Re: [gentoo-dev] virtualx eclass

[Doug Goldstein]

Doug Goldstein wrote:
> While the rule of thumb has been if an eclass needs something it should
> provide it's own depends. However the virtualx eclass needs to be
> different simply because in some cases it's only uses for tests (this is
> it's most common usage in the whole) tree. When it's used for tests
> pulling in the xorg-server the most ideal situation would be if
> xorg-server was only pulled in on USE=test because currently for anyone
> emerging an app that uses GTK+ they have a weird situation in the fact
> that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
> most usages of the X USE flag), however GTK+ itself due to it's usage of
> the virtualx eclass pulls in xorg-server when USE=X, which is only used
> for tests. This results in a confusing experience for users looking to
> built a headless machine.
>
> It'd be a lot more consistent if ebuilds provided a USE flag or directly
> depended on the xorg-server and then used the functions in the eclass.
> So in summary, those are the changes I plan on making very shortly. If
> someone's got some input, please speak up.
>
>   
Alright... after talking to Diego, Dave, and Remi the final result that
I've come up with is the following:

VIRTUALX_CONDITIONAL_USE="test"

inherit virtualx

That'll result in virtualx adding the following:

DEPEND="test? ( x11-base/xorg-server x11-apps/xhost )"

if VIRTUALX_CONDITIONAL_USE is unset (as it will be for all ebuilds
initially) the default will be "X". Which means the default is the same
as what we've got today. If it's set to an empty string, it'll always be
required. Otherwise, it will use the supplied USE flag.

--
Doug Goldstein

Re: [gentoo-dev] virtualx eclass

[Donnie Berkholz]

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On 11:35 Thu 16 Oct     , Doug Goldstein wrote:
> Doug Goldstein wrote:
> > While the rule of thumb has been if an eclass needs something it should
> > provide it's own depends. However the virtualx eclass needs to be
> > different simply because in some cases it's only uses for tests (this is
> > it's most common usage in the whole) tree. When it's used for tests
> > pulling in the xorg-server the most ideal situation would be if
> > xorg-server was only pulled in on USE=test because currently for anyone
> > emerging an app that uses GTK+ they have a weird situation in the fact
> > that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
> > most usages of the X USE flag), however GTK+ itself due to it's usage of
> > the virtualx eclass pulls in xorg-server when USE=X, which is only used
> > for tests. This results in a confusing experience for users looking to
> > built a headless machine.
> >
> > It'd be a lot more consistent if ebuilds provided a USE flag or directly
> > depended on the xorg-server and then used the functions in the eclass.
> > So in summary, those are the changes I plan on making very shortly. If
> > someone's got some input, please speak up.
> >
> >   
> Alright... after talking to Diego, Dave, and Remi the final result that
> I've come up with is the following:
> 
> VIRTUALX_CONDITIONAL_USE="test"
> 
> inherit virtualx
> 
> That'll result in virtualx adding the following:
> 
> DEPEND="test? ( x11-base/xorg-server x11-apps/xhost )"
> 
> if VIRTUALX_CONDITIONAL_USE is unset (as it will be for all ebuilds
> initially) the default will be "X". Which means the default is the same
> as what we've got today. If it's set to an empty string, it'll always be
> required. Otherwise, it will use the supplied USE flag.

I'm not sure whether this would work, but one idea would be to handle 
dependencies depending on what's in IUSE of the ebuild inheriting.

-- 
Thanks,
Donnie

Donnie Berkholz
Developer, Gentoo Linux
Blog: http://dberkholz.wordpress.com

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Re: [gentoo-dev] virtualx eclass

[Bo Ørsted Andresen]

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On Thursday 16 October 2008 23:54:32 Donnie Berkholz wrote:
> I'm not sure whether this would work, but one idea would be to handle
> dependencies depending on what's in IUSE of the ebuild inheriting.

That would require ebuilds to set IUSE before inheriting the eclass.

-- 
Bo Andresen

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Re: [gentoo-dev] virtualx eclass

[Doug Goldstein]

Doug Goldstein wrote:
> Doug Goldstein wrote:
>   
>> While the rule of thumb has been if an eclass needs something it should
>> provide it's own depends. However the virtualx eclass needs to be
>> different simply because in some cases it's only uses for tests (this is
>> it's most common usage in the whole) tree. When it's used for tests
>> pulling in the xorg-server the most ideal situation would be if
>> xorg-server was only pulled in on USE=test because currently for anyone
>> emerging an app that uses GTK+ they have a weird situation in the fact
>> that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
>> most usages of the X USE flag), however GTK+ itself due to it's usage of
>> the virtualx eclass pulls in xorg-server when USE=X, which is only used
>> for tests. This results in a confusing experience for users looking to
>> built a headless machine.
>>
>> It'd be a lot more consistent if ebuilds provided a USE flag or directly
>> depended on the xorg-server and then used the functions in the eclass.
>> So in summary, those are the changes I plan on making very shortly. If
>> someone's got some input, please speak up.
>>
>>   
>>     
> Alright... after talking to Diego, Dave, and Remi the final result that
> I've come up with is the following:
>
> VIRTUALX_CONDITIONAL_USE="test"
>
> inherit virtualx
>
> That'll result in virtualx adding the following:
>
> DEPEND="test? ( x11-base/xorg-server x11-apps/xhost )"
>
> if VIRTUALX_CONDITIONAL_USE is unset (as it will be for all ebuilds
> initially) the default will be "X". Which means the default is the same
> as what we've got today. If it's set to an empty string, it'll always be
> required. Otherwise, it will use the supplied USE flag.
>
>   
Turns out this situation breaks down when multiple USE flags are
required/used. One suggestion is to allow for that via:

VIRTUALX_CONDITIONAL_USE="test X"

but needs someone to write some elegant shell to make that expansion
happen. Also, it'll happen in the global scope when the data is cached
so a little ugh on that part.

The last fall back of course is to go to just defining VIRTUALX_DEPS and
letting each ebuild USE it how it needs to use it.

Feedback, comments, etc are appreciated.

--
Doug Goldstein

Re: [gentoo-dev] virtualx eclass

[Petteri Räty]

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Doug Goldstein wrote:
> Doug Goldstein wrote:
>> Doug Goldstein wrote:
>>   
>>> While the rule of thumb has been if an eclass needs something it should
>>> provide it's own depends. However the virtualx eclass needs to be
>>> different simply because in some cases it's only uses for tests (this is
>>> it's most common usage in the whole) tree. When it's used for tests
>>> pulling in the xorg-server the most ideal situation would be if
>>> xorg-server was only pulled in on USE=test because currently for anyone
>>> emerging an app that uses GTK+ they have a weird situation in the fact
>>> that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
>>> most usages of the X USE flag), however GTK+ itself due to it's usage of
>>> the virtualx eclass pulls in xorg-server when USE=X, which is only used
>>> for tests. This results in a confusing experience for users looking to
>>> built a headless machine.
>>>
>>> It'd be a lot more consistent if ebuilds provided a USE flag or directly
>>> depended on the xorg-server and then used the functions in the eclass.
>>> So in summary, those are the changes I plan on making very shortly. If
>>> someone's got some input, please speak up.
>>>
>>>   
>>>     
>> Alright... after talking to Diego, Dave, and Remi the final result that
>> I've come up with is the following:
>>
>> VIRTUALX_CONDITIONAL_USE="test"
>>
>> inherit virtualx
>>
>> That'll result in virtualx adding the following:
>>
>> DEPEND="test? ( x11-base/xorg-server x11-apps/xhost )"
>>
>> if VIRTUALX_CONDITIONAL_USE is unset (as it will be for all ebuilds
>> initially) the default will be "X". Which means the default is the same
>> as what we've got today. If it's set to an empty string, it'll always be
>> required. Otherwise, it will use the supplied USE flag.
>>
>>   
> Turns out this situation breaks down when multiple USE flags are
> required/used. One suggestion is to allow for that via:
> 
> VIRTUALX_CONDITIONAL_USE="test X"
> 
> but needs someone to write some elegant shell to make that expansion
> happen. Also, it'll happen in the global scope when the data is cached
> so a little ugh on that part.
> 

Huh?

VIRTUALX_DEPS="<insert eclass needed atoms here>"
for flag in ${VIRTUALX_CONDITIONAL_USE}; do
	DEPEND="${DEPEND} ${flag}? ( ${VIRTUALX_DEPS )"
done

Am I missing something here?
The ebuild itself can then check if both need to be enabled etc.

Regards,
Petteri


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Re: [gentoo-dev] virtualx eclass

[Doug Goldstein]

Petteri Räty wrote:
> Doug Goldstein wrote:
>   
>> Doug Goldstein wrote:
>>     
>>> Doug Goldstein wrote:
>>>   
>>>       
>>>> While the rule of thumb has been if an eclass needs something it should
>>>> provide it's own depends. However the virtualx eclass needs to be
>>>> different simply because in some cases it's only uses for tests (this is
>>>> it's most common usage in the whole) tree. When it's used for tests
>>>> pulling in the xorg-server the most ideal situation would be if
>>>> xorg-server was only pulled in on USE=test because currently for anyone
>>>> emerging an app that uses GTK+ they have a weird situation in the fact
>>>> that all of GTK+'s depends that have USE=X use it to mean libX11 (as do
>>>> most usages of the X USE flag), however GTK+ itself due to it's usage of
>>>> the virtualx eclass pulls in xorg-server when USE=X, which is only used
>>>> for tests. This results in a confusing experience for users looking to
>>>> built a headless machine.
>>>>
>>>> It'd be a lot more consistent if ebuilds provided a USE flag or directly
>>>> depended on the xorg-server and then used the functions in the eclass.
>>>> So in summary, those are the changes I plan on making very shortly. If
>>>> someone's got some input, please speak up.
>>>>
>>>>   
>>>>     
>>>>         
>>> Alright... after talking to Diego, Dave, and Remi the final result that
>>> I've come up with is the following:
>>>
>>> VIRTUALX_CONDITIONAL_USE="test"
>>>
>>> inherit virtualx
>>>
>>> That'll result in virtualx adding the following:
>>>
>>> DEPEND="test? ( x11-base/xorg-server x11-apps/xhost )"
>>>
>>> if VIRTUALX_CONDITIONAL_USE is unset (as it will be for all ebuilds
>>> initially) the default will be "X". Which means the default is the same
>>> as what we've got today. If it's set to an empty string, it'll always be
>>> required. Otherwise, it will use the supplied USE flag.
>>>
>>>   
>>>       
>> Turns out this situation breaks down when multiple USE flags are
>> required/used. One suggestion is to allow for that via:
>>
>> VIRTUALX_CONDITIONAL_USE="test X"
>>
>> but needs someone to write some elegant shell to make that expansion
>> happen. Also, it'll happen in the global scope when the data is cached
>> so a little ugh on that part.
>>
>>     
>
> Huh?
>
> VIRTUALX_DEPS="<insert eclass needed atoms here>"
> for flag in ${VIRTUALX_CONDITIONAL_USE}; do
> 	DEPEND="${DEPEND} ${flag}? ( ${VIRTUALX_DEPS )"
> done
>
> Am I missing something here?
> The ebuild itself can then check if both need to be enabled etc.
>
> Regards,
> Petteri
>
>   
All that's going to do is create the following..

DEPEND="X? ( ${VIRTUALX_DEPS} ) test? ( ${VIRTUALX_DEPS} )"

Which would make it depend on the dependencies when either USE="test" or
USE="X", which is not what we want. We want it when BOTH are set.

Right now there's no viable solution short of my original proposal which
involves having each ebuild stick ${VIRTUALX_DEPS} where it needs them.