[MacPorts] #33489: MPlayer @1.0rc4 - hidden dependencies

[MacPorts]

#33489: MPlayer @1.0rc4 - hidden dependencies
---------------------------+------------------------------------------------
 Reporter:  hans@…         |       Owner:  macports-tickets@…                   
     Type:  defect         |      Status:  new                                  
 Priority:  Normal         |   Milestone:                                       
Component:  ports          |     Version:  2.0.4                                
 Keywords:                 |        Port:  MPlayer                              
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Changes (by ecronin@…):

 * cc: acho@…, cal@… (added)


Old description:

> MPlayer has hidden dependencies. At least, it silently picks up audio
> /opencore-amr and multimedia/ffmpeg.
>
> That is not exactly a surprise, given that the Portfile contains the
> following misguided comment:
>
> # MPlayer autodetects many support libs.  To prevent undeclared
> # dependencies, explicitly disable everything optional first.
> # Later, let autodetect do its magic not explicit --enable
>
> Letting autodetect "do its magic" without explicitly --enabling
> the stuff AND explicitly mentioning it in depends_lib
> is exactly how undeclared dependencies are created!
>
> For example, I just "port uninstall"ed ffmpeg and opencore-amr
> - the installed MPlayer port didn't object, but running mplayer
> of course crashed immediately, as mplayer silently depends on those (and
> most probably many others).
>
> Attached is a diff to the Portfile which --disables the
> opencore-amr functionality, and adds an explicit dependency
> on ffmpeg.
>
> I did only this, as I maintain opencore-amr and use ffmpeg,
> so I stumbled upon this iceberg tip. I leave it to the maintainers of
> MPlayer to go through all the enable/disable options
> of MPlayer's ./configure, explicitly enable those that they want,
> explicitly name them as a library dependency once enabled, and explicitly
> disabling those they do not want (without having that
> --disables be later overriden by automagic silent detection).

New description:

 MPlayer has hidden dependencies. At least, it silently picks up audio
 /opencore-amr and multimedia/ffmpeg.

 That is not exactly a surprise, given that the Portfile contains the
 following misguided comment:

 {{{
 # MPlayer autodetects many support libs.  To prevent undeclared
 # dependencies, explicitly disable everything optional first.
 # Later, let autodetect do its magic not explicit --enable
 }}}

 Letting autodetect "do its magic" without explicitly --enabling
 the stuff AND explicitly mentioning it in depends_lib
 is exactly how undeclared dependencies are created!

 For example, I just "port uninstall"ed ffmpeg and opencore-amr
 - the installed MPlayer port didn't object, but running mplayer
 of course crashed immediately, as mplayer silently depends on those (and
 most probably many others).

 Attached is a diff to the Portfile which --disables the
 opencore-amr functionality, and adds an explicit dependency
 on ffmpeg.

 I did only this, as I maintain opencore-amr and use ffmpeg,
 so I stumbled upon this iceberg tip. I leave it to the maintainers of
 MPlayer to go through all the enable/disable options
 of MPlayer's ./configure, explicitly enable those that they want,
 explicitly name them as a library dependency once enabled, and explicitly
 disabling those they do not want (without having that
 --disables be later overriden by automagic silent detection).

--

Comment:

 First, you probably should be looking at mplayer-devel or mplayer2.  The
 MPlayer port is dead and should just be removed from ports since all it
 seems to do is cause confusion (it still builds most of the time which is
 why I'm hesitant to just replaced_by it in case someone really does think
 a 5 year old completely unsupported by upstream release candidate is
 better than a slightly less unsupported by upstream port with -devel in
 its name)

 Regarding that comment, the "let autodetect do its magic" part means that
 explicit {{{--enable-foo}}} or {{{--enable-foo=/opt/local}}} do not do the
 right thing with (ancient) mplayer's ./configure.  To enable a feature you
 really do need to remove the --disable-foo flag but just let ./configure
 autodetect that foo is present, instead of adding --enable-foo like you do
 in normal autoconf'd programs.  But the removing of --disable-foo only
 happens inside variant blocks where the necessary depends are added, e.g.:

 {{{
 variant aa \
     description {Enable animated ASCII art video output} {
     depends_lib-append      port:aalib
     configure.args-delete   --disable-aa
 }
 }}}

 This is obviously very brittle, and it looks like some new knobs got added
 at some point for libraries that didn't exist in macports years ago.
 ffmpeg is odd since it used to always use a private internal copy and not
 link against the system version...  In fact in comment 2 I don't see
 ffmpeg listed there.  Are you sure it was complaining about ffmpeg and not
 just opencore-amr?

 I'm cc'ing the mplayer-devel and mplayer2 maintainers since they may have
 similar issues where new autodetected libraries have been added to
 ./configure that need to be explicitly disabled in the Portfile

-- 
Ticket URL: <https://trac.macports.org/ticket/33489#comment:2>
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