[yocto] Using PACKAGECONFIG

[Gary Thomas]

On 2015-04-09 08:16, Paul Eggleton wrote:
> Hi Gary,
>
> On Thursday 09 April 2015 07:45:47 Gary Thomas wrote:
>> I'm trying to extend PACKAGECONFIG for a recipe (vlc).  The
>> main recipe contains this:
>>     PACKAGECONFIG ?= " live555"
>>     PACKAGECONFIG[mad] = "--enable-mad,--disable-mad,libmad"
>>     PACKAGECONFIG[a52] = "--enable-a52,--disable-a52,liba52"
>>     PACKAGECONFIG[jack] = "--enable-jack,--disable-jack,jack"
>>     PACKAGECONFIG[live555] = "--enable-live555,--disable-live555,live555"
>>     PACKAGECONFIG[libass] = "--enable-libass,--disable-libass,libass"
>>     PACKAGECONFIG[mkv] = "--enable-mkv,--disable-mkv,libmatroska libebml"
>>     PACKAGECONFIG[postproc] =
>> "--enable-postproc,--disable-postproc,libpostproc" PACKAGECONFIG[opencv] =
>> "--enable-opencv,--disable-opencv,opencv" PACKAGECONFIG[libva] =
>> "--enable-libva --enable-avcodec,--disable-libva --disable-avcodec,libva
>> libav"
>>
>> I'd like to only add "libva" to the default, so I wrote this
>> in my local.conf:
>>     PACKAGECONFIG_pn-vlc_append = " libva"
>> Inspecting it
>>     $ bitbake vlc -e | grep ^PACKAGECONFIG
>>     PACKAGECONFIG=" libva"
>>
>> Oops.  Just to be sure, I tried
>>     PACKAGECONFIG_pn-vlc = "live555 libva"
>> which gives
>>     $ bitbake vlc -e | grep ^PACKAGECONFIG
>>     PACKAGECONFIG="live555 libva"
>>
>> Note: I tried
>>     PACKAGECONFIG_append_pn-vlc = " libva"
>> which does work.  However, I've also used
>>     PACKAGECONFIG_pn-chromium_append = " component-build"
>> for a different recipe that does work... VERY CONFUSED
>>
>> What am I doing wrong?  How do I correctly add to the default list?
>
> In general, for a conditional append, you must use _append_<override> - the
> other way around will not do an append, AFAIK it will just set the value.
>
> There are some other valid options that you didn't mention above:
>
> 1) Set it outright to list all of the options you want instead of appending.
> At least you know exactly what is going into the value. (I know some people
> don't like this.)
>
> 2) Set it using += or _append from a bbappend.

Thanks for the explanation - I'll make sure to use the correct
form from now on (and fix my incorrect uses for chromium!)

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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