Questions on dependencies

[Craig Treleaven]

At 11:48 AM -0500 11/9/13, Jeremy Lavergne wrote:
>>Myth includes Perl and Python bindings that need a number of 
>>dependencies to work (eg port:${pymodver}-mysql, 
>>port:${perlmodver}-dbd-mysql, etc).  I have these listed as 
>>depends_lib but no Myth binaries link directly to them.  Is it 
>>advantageous to list them instead as depends_run?
>
>The packages aren't guaranteed to be available during build time if 
>it's only a depends_run. You might need them listed in both 
>depends_build and depends_run, if the bindings aren't always built.
>
>>egall's script says that Myth does not link directly to 
>>qt4-mac-${mysqlver}-plugin but does link directly to qt4-mac. 
>>Again, are there advantages to showing qt4-mac as a depends_lib but 
>>the plugin as a depends_run?
>
>Again, qt4-mac should definitely be listed as depends_lib, but the 
>plugin might need both _run and _build.
>
>Try setting the plugin dependency to _run and deactivate it, then 
>build and see if your package still uses it. If so, then the plugin 
>isn't needed during _build. If it doesn't work then you need it in 
>both _build and _run.

So, in a way, we all use depends_lib for certain things as a 
short-hand for listing stuff as both depends_build and depends_run, 
no?  For example, I was looking at some of the perl modules.  My port 
uses p5.12-libwww-perl which relies on a list of other perl modules. 
Using port-depcheck confirms that no compiled library links.  Of the 
rdeps for p5.12-libwww-perl, only a couple of lower level modules 
appear to link directly to a compiled library, eg p5.12-net-ssleay.

In a perfect world, maybe we should have a "depends_mod" for 
indicating a dependency on an interpreted module (perl, python, php, 
ruby, ...)?  It would express the relationship more precisely, I 
think.  OTOH, I don't see any particular advantage other than that 
and it would be a tremendous amount of work to got through all 
existing ports and split depends_mod out from depends_lib as 
necessary.  Perhaps just the documentation for depends_lib should be 
expanded to say that it indicates both compiled and interpreted 
linkages?

Craig