[MacPorts] #60995: port_binary_distributable.tcl: Clarify reason for nondistributability

[MacPorts]

#60995: port_binary_distributable.tcl: Clarify reason for nondistributability
---------------------------+---------------------
 Reporter:  ryandesign     |      Owner:  admin@…
     Type:  enhancement    |     Status:  new
 Priority:  Normal         |  Milestone:
Component:  buildbot/mpbb  |    Version:
 Keywords:                 |       Port:
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 Could port_binary_distributable.tcl in verbose mode provide more details
 on why a port is not distributable? Many developers, myself included,
 struggle to understand what if anything can be done to resolve
 nondistributability when the only information the script provides is e.g.:

 {{{
 "emacs-app" is not distributable because its license "gpl" conflicts with
 license "OpenSSL" of dependency "openssl"
 }}}

 It is not easy for a developer to figure out the chain of dependencies
 that leads to the dependency with the conflicting license. `port rdeps`
 doesn't help because it only lists each dependency once, even if that one
 occurrence is in a dependency chain that is not participating in
 distributability checks due to `installs_libs no`, and `port rdeps --full`
 produces too much output to be usable.

 The problem is made more difficult when a port has different dependencies
 on different OS versions (e.g. due to needing a newer compiler or cctools
 or git on older systems), resulting in different distributability on
 different OS versions (#54633, #59926). Maintainers usually doesn't have
 direct access to multiple OS version to investigate.

 I have often wanted to have a MacPorts command to show the chain(s) of
 dependencies relating one port to another. Maybe if that existed,
 port_binary_distributable.tcl could use it.

-- 
Ticket URL: <https://trac.macports.org/ticket/60995>
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