[MacPorts] #37808: RFE: Add a "minor" variable to the perl portgroup

[MacPorts]

#37808: RFE: Add a "minor" variable to the perl portgroup
--------------------------+--------------------------------
  Reporter:  egall@…      |      Owner:  macports-tickets@…
      Type:  enhancement  |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.1.2
Resolution:               |   Keywords:
      Port:               |
--------------------------+--------------------------------

Comment (by egall@…):

 Replying to [comment:1 ryandesign@…]:
 > The portgroup cannot know the actual version number of perl, since perl
 might not be installed yet at the time that the portgroup is being
 included into a portfile.
 >
 > What is the use case for which you need to know this?

 Well this might just be me being bad/new at writing portfiles, but I was
 trying to write a portfile for `cpan2port`, and for some reason it gave me
 the following error during the destroot phase:
 {{{
     Error: org.macports.destroot for port p5.12-cpan2port returned:
 /opt/local/var/macports/build/_opt_local_var_macports_sources_local_perl_p5-cpan2port/p5.12-cpan2port/work/destroot/opt/local/lib/perl5/vendor_perl/5.12.4:
 no such file or directory
 }}}
 Now I didn't know why it was trying to do that, as I never asked it to
 make such a directory (I'm assuming the perl portgroup did?), but anyway,
 I tried to get around it by adding the following line of code:
 {{{
     xinstall -d
 ${destroot}${prefix}/lib/perl5/vendor_perl/${perl5.major.minor}
 }}}
 And of course that errorred out because "minor" isn't actually a thing.
 idk, maybe I shouldn't even be using the perl portgroup at all for this
 port, but still, I think it'd be useful to have a "minor" variable anyway
 regardless of this use case. I can understand if it's not feasible though.
 Although then again, one thing I'm wondering, is why is the value of the
 variable being determined at include time? Couldn't it be determined at
 runtime? I don't really know that much about Tcl or MacPorts's internals,
 so forgive me if that's a stupid question...

-- 
Ticket URL: <https://trac.macports.org/ticket/37808#comment:2>
MacPorts <http://www.macports.org/>
Ports system for Mac OS