[MacPorts] #60700: Warning: cltversion: The Command Line Tools are installed, but MacPorts cannot determine the version.

[MacPorts]

#60700: Warning: cltversion: The Command Line Tools are installed, but MacPorts
cannot determine the version.
-------------------------+----------------------
  Reporter:  ryandesign  |      Owner:  (none)
      Type:  defect      |     Status:  new
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.6.2
Resolution:              |   Keywords:  catalina
      Port:              |
-------------------------+----------------------

Comment (by ryandesign):

 Replying to [comment:8 cjones051073]:
 > Thats is only an issue because of MPs insistence that the SDK must match
 the OS. Its not a requirement from the Apple/Xcode side, where as we have
 seen using a different one is fine, and actually what they promote (like
 right now where the latest macOS 10.14 Xcode uses 10.15 SDK).

 I know that Apple promotes that for Mac app development. My understanding
 is it's not appropriate for the open source software we build in MacPorts
 however because open source software written for other operating systems
 is not aware of Apple's recommendations regarding weak linking. For
 example, a program compiled on OS X 10.11 with Xcode 8, which only
 contains the macOS 10.12 SDK, would determine from that SDK that
 `clock_gettime` is available and would try to use it. This would fail to
 run on 10.11 because `clock_gettime` is only available on 10.12 and later.

 > I was just pointing out, right now there is no Xcode for mac10.15 with
 an 10.16 (or 11.0) SDK, so just removing the CLT completely would fix it.

 Xcode 12 beta is already available. I am assuming it contains only the
 11.0 SDK, but I can't expand the xip on this machine for some reason.

 > In the future, if (as I personally expect) Apple completely depreciates
 the CLT, then we will not be able to use this to solve the Xcode SDK
 issue, so we will need another way round it.

 Per above, that would break a lot of open source software so I hope they
 do not do that.

-- 
Ticket URL: <https://trac.macports.org/ticket/60700#comment:10>
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