[MacPorts] #33259: cmake portgroup: out of source build option, possibly by default

[MacPorts]

#33259: cmake portgroup: out of source build option, possibly by default
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  Reporter:  ryandesign@…  |      Owner:  macports-tickets@…
      Type:  enhancement   |     Status:  new
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:
Resolution:                |   Keywords:
      Port:                |
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Comment (by ryandesign@…):

 Replying to [comment:23 mojca@…]:
 > Setting something like
 > {{{
 > configure.dir ${workpath}/build/i386
 > }}}
 > would probably no longer resolve "`../${worksrcdir}`" properly. I
 believe that using `${worksrcpath}` is safer from that respect.

 Yes, you're right.

 Replying to [comment:24 rjvbertin@…]:
 > The role of `default` would be to set a default value that is applied
 when the variable hasn't been set already, no? That was how I saw its use
 in any case,

 Yes, that's correct. It sets a default, which ports can still override if
 needed. Notably, if you write `default someoption {somevalue}`, then it
 does not matter if the portfile sets someoption to another value before or
 after including the portgroup; it'll work either way (the portfile's value
 will be used and the default will not). Whereas if you wrote `someoption
 somevalue` in a portgroup, if a portfile set the value before including
 the portgroup, the portgroup's value would override the portfile's.

 > I guess I should have stated that the OOT had to be set before including
 the port group (did you test that?).

 Portgroups should not be written to require that.

-- 
Ticket URL: <https://trac.macports.org/ticket/33259#comment:25>
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