Breaking long dependency chains

[Ryan Schmidt]

On Mar 18, 2012, at 20:35, Ryan Schmidt wrote:

> MacPorts only depends on MacPorts subversion for fetch.type svn if the OS version of Subversion is too old -- that is, on Leopard -- or missing -- that is, on Tiger.

Just to elaborate on this slightly: even though "port deps netpbm" shows a fetch dependency on subversion, that does not mean that the subversion port will necessarily be installed.

$ port deps netpbm
Full Name: netpbm @10.47.31_0
Fetch Dependencies:   subversion
Build Dependencies:   perl5
Library Dependencies: zlib, jpeg, tiff, libpng, jasper, jbigkit, libxml2

If you look at the verbose dependencies, you'll see:

$ port -v deps netpbm
Full Name: netpbm @10.47.31_0
Fetch Dependencies:   bin:svn:subversion
Build Dependencies:   path:bin/perl:perl5
Library Dependencies: port:zlib, port:jpeg, port:tiff, port:libpng, port:jasper, port:jbigkit, port:libxml2

This is on Snow Leopard, where the system version of subversion is new enough, therefore it's a "bin" dependency which can be satisfied by any available binary, including the system one (rather than a "port" dependency which can only be satisfied by a MacPorts port).