[MacPorts] #64321: MacPorts 2.7.1: build from source fails MacOs Big Sur 11.6.2 with "configure: error: tcl.h not found."

[MacPorts]

#64321: MacPorts 2.7.1: build from source fails MacOs Big Sur 11.6.2 with
"configure: error: tcl.h not found."
---------------------+--------------------
  Reporter:  purist  |      Owner:  (none)
      Type:  defect  |     Status:  new
  Priority:  Normal  |  Milestone:
 Component:  base    |    Version:  2.7.1
Resolution:          |   Keywords:
      Port:          |
---------------------+--------------------

Comment (by purist):

 Oh I'm rusty, I didn't think of the log file...

 I've attached the whole log file for running the vanilla "./configure"
 with no args. These might the the lines you're looking for:

 {{{
 configure:8607: === configuring in vendor/tcl/unix (/Volumes/Big
 LaCie/p/sw2/MacPorts-2.7.1/vendor/tcl/unix)
 configure:8866: running /bin/sh ./configure '--cache-file=/dev/null'
 '--disable-option-checking'  '--prefix=/opt/local/libexec/macports'
 '--enable-threads' '--srcdir=.' 'CC=clang' in vendor/tcl/unix
 configure:8872: === finished configuring in vendor/tcl/unix (/Volumes/Big
 LaCie/p/sw2/MacPorts-2.7.1/vendor/tcl/unix)
 configure:8933: === configuring in vendor/thread (/Volumes/Big
 LaCie/p/sw2/MacPorts-2.7.1/vendor/thread)
 configure:9192: running /bin/sh ./configure '--cache-file=/dev/null'
 '--disable-option-checking'  '--prefix=/opt/local/libexec/macports' '--
 srcdir=.' 'CC=clang' in vendor/thread
 configure:9194: error: configure failed for vendor/thread
 }}}

 seems like "./configure" chose "vendor/tcl/unix" instead of
 "vendor/tcl/macosx"- is this what's causing my issue?

-- 
Ticket URL: <https://trac.macports.org/ticket/64321#comment:2>
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