[MacPorts] #57137: xcode portgroup should set -derivedDataPath on Xcode versions that need it

[MacPorts]

#57137: xcode portgroup should set -derivedDataPath on Xcode versions that need it
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  Reporter:  ryandesign     |      Owner:  (none)
      Type:  enhancement    |     Status:  new
  Priority:  Normal         |  Milestone:
 Component:  ports          |    Version:
Resolution:                 |   Keywords:
      Port:  xcode-1.0.tcl  |
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Comment (by ryandesign):

 Replying to [comment:2 kencu]:
 > I noticed three things that appear to be general xcode PG issues while
 fixing aquaterm and looking over irrlicht...
 >
 > 1. why do we run a build phase, when the build always seems to occur
 again in the destroot phase anyway, and sometimes this causes errors?

 I have noticed that some Xcode-using ports do that. I do not know why that
 happens. Some Xcode-using ports override the destroot phase entirely,
 perhaps in order to combat that. In MacPorts we should be building in the
 build phase and destrooting in the destroot phase. If we are not doing
 that for Xcode-using ports, we should figure out a way to fix that.

 > 2. the -derivedDataPath issue
 > 3. at least on Xcode 10, the -derivedDataPath flag is only accepted if
 there is a scheme, which so far seems to be the same as ${xcode.target}
 >
 > SO -- I am wondering if the xcode PG might just add the following as a
 default, as it seems to be working for me so far on several ports:
 > {{{
 > build                   {}
 > destroot.pre_args       -derivedDataPath ./DerivedData
 > xcode.scheme            ${xcode.target}
 > }}}

 I wasn't aware that Xcode required a scheme to use the derived data path.

 A scheme is not the same thing as a target, that's why there are separate
 settings in the portgroup.

-- 
Ticket URL: <https://trac.macports.org/ticket/57137#comment:3>
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