[MacPorts] #72503: nodejs22 doesn't build with Xcode 13.2 tools installed: clang++ never updates to clang++-mp-17

[MacPorts]

#72503: nodejs22 doesn't build with Xcode 13.2 tools installed: clang++ never
updates to clang++-mp-17
------------------------+--------------------
 Reporter:  mhjacobson  |      Owner:  (none)
     Type:  defect      |     Status:  new
 Priority:  Normal      |  Milestone:
Component:  ports       |    Version:
 Keywords:              |       Port:
------------------------+--------------------
 On macOS Big Sur 11.7.10 20G1427, with the Xcode 13.2 command-line tools
 installed, nodejs22 fails to build.  AFAICT, here is what happens:

 0. `configure.compiler` initially resolves to `clang`

 1. In the Portfile, line 73 says:

   # suppress a warning-as-error that shows up with newer clang compilers
   if {[string match *clang* ${configure.compiler}]} {
       configure.cxx-append      -Wno-error=enum-constexpr-conversion

       #the ventura buildbot will fail because it doesn't recognise this
 flag
       #so we disable unknown warnings as errors for older compilers
       configure.cxx-append      -Wno-error=unknown-warning-option
   }

 which goes ahead and resolves `configure.cxx` to `/usr/bin/clang`

 2. Later in the Portfile, line 161 does:

   # The Node.js docs says it requires "Xcode >= 13 (Apple LLVM >= 12)" [1]
   # and accordingly the compile fails on macOS 11.7 Big Sur with Xcode's
   # clang. However, bumping the requirement for clang 1400 or greater
   # gets it to successfully compile.
   # [1] https://github.com/nodejs/node/blob/v22.x/BUILDING.md#supported-
 toolchains
   compiler.blacklist-append {clang < 1400}

 This causes `configure.compiler` to be re-evaluated to `macports-
 clang-17`.

 3. However, it's too late: step #2 already baked in `/usr/bin/clang++`.

 4. Node.js 22 fails to build with the clang++ from Xcode 13.2, because its
 libc++ headers don't support std::shared_ptr of array type (since fixed
 here: <https://reviews.llvm.org/D80882>).

 I suspect this was broken by commit
 eb8d9a670797a8f6b569675576844aaba007356f.

-- 
Ticket URL: <https://trac.macports.org/ticket/72503>
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