Any common policy against conflicting choice in Makefile OPTIONS?

[Olli Hauer]

On 2012-02-05 18:23, Chris Rees wrote:
> On 5 February 2012 17:21, Olli Hauer <ohauer at freebsd.org> wrote:
>> On 2012-02-05 17:19, RyōTa SimaMoto wrote:
>>> Hi, I'm a port maintainer for multimedia/qmmp, and some ports.
>>> Before upgrading QMMP port, may I ask what is the common policy how to
>>> offer Makefile OPTIONS containing a certain contradictory pair?
>>>
>>> Actually the latest version of QMMP supports several versions of ffmpeg,
>>> including 0.7.11, 0.9, 0.9.1, and 2012.01.22 that I tested to verify, so it
>>> allows user to choose one of multimedia/ffmpeg or multimedia/ffmpeg-devel.
>>> As you know you should not select both of them, otherwise they may conflict
>>> with each other.  I plan to provide an entry for each of them.
>>>   | ....
>>>   | [*] FFMPEG        Support to playback by FFMPEG
>>>   | [ ] FFMPEG_DEVEL  Support to playback by FFMPEG-devel
>>>   | ....
>>> Then how should the Makefile proceed after the user's choice?
>>>
>>> When the user did not install any of them yet, it's easy: The installation
>>> would obey the user's order except when occationally both of them are
>>> enabled that results to fail with an alert message.  On the other hand, if
>>> one of them are already installed, Makefile would know which one is
>>> installed using 'exists(${LOCALBASE}/include/libavcodec/vda.h)' command.
>>> So, in fact, there is no question that which version the user want to use.
>>>
>>> The smartest way would be that provides a single entry which corresponds
>>> to the existing version and hides the other entry that should not be
>>> choosen.  Unfortunately, the value LOCALBASE is not defined until
>>> <bsd.port.options.mk> macro is loaded, that means we don't have any proper
>>> steps to determine what version is already installed when the Makefile
>>> construct the OPTIONS set.  So we have no other way than to let the option
>>> dialog always show both entries including quite wrong option.
>>>
>>> Then if the user selects the other one that might conflict with the
>>> installed version, there are six possible courses I assume.
>>>  0x000.  Quit the session with alert message instructing user to retry
>>>          'make config' to choose the already installed one that Makefile
>>>          knows.
>>>  0x001.  Dare to go through and expect that the depending port deals with
>>>          the conflicting issue.
>>>  0x002.  Use the installed version and omit the choice implicitly.
>>>  0x004.  Warn with short pause, then use the installed version and omit
>>>          the choice.
>>>  0x010.  Store options into /var/db/ports/* as are that the user selects.
>>>  0x020.  Store options into /var/db/ports/* with correction as actually
>>>          working.  (If option variables are allowed to be changed at
>>>          testing stage.)
>>>
>>> Is there any recommended policy?  If so, what way or a set of ways should I
>>> choose?
>>>
>>>
>>
>> The following patch will do what you want, just polish the IGNORE messages.
>> Hopefully the include files do not change with the next versions.
>>
>>
>>
>>
>> --- Makefile.orig       2012-02-05 17:53:58.000000000 +0100
>> +++ Makefile    2012-02-05 18:16:00.000000000 +0100
>> @@ -35,6 +35,7 @@
>>                FLAC    "Support to playback FLAC files" on \
>>                MUSEPACK        "Support to playback MPC files" on \
>>                FFMPEG  "Support to playback FFMPEG files" on \
>> +               FFMPEG_DEVEL    "Support to playback FFMPEG-devel files" on \
> 
> Hm, breaks itself by default ;)

where?
(Maybe I had not enough sleep tomight)



> I still think depending on ffmpeg binary and defaulting to
> multimedia/ffmpeg and just having the one OPTION is the simplest
> solution.

Sure, but the OP maybe wants to give the ability to choose which ffmpeg version in case the ffmpeg port is not already installed.