Python problems on OS X

[Andrew Butterfield]

I keep getting a python error when trying to build the tool suite on 
OS X. The end of the error log is:

```
checking whether to use python... /Library/Frameworks/Python.framework/Versions/2.7/bin/python2
checking for python... no
configure: error: no usable python found at /Library/Frameworks/Python.framework/Versions/2.7/bin/python2
make[1]: *** [configure-gdb] Error 1
make: *** [all] Error 2
shell cmd failed: /bin/sh -ex  /Users/butrfeld/REPOS/esa-qual/modules/rsb/rtems/build/sparc-rtems6-gdb-0295dde-x86_64-apple-darwin19.6.0-1/do-build
error: building sparc-rtems6-gdb-0295dde-x86_64-apple-darwin19.6.0-1

```

What are the criteria for python to be "useable"?

I have removed all traces of non-native (brew) pythons that I can find.

I followed the virtual environment instructions in the rtems-central README.md

:- which python
/Library/Frameworks/Python.framework/Versions/2.7/bin/python2

:- which python3
/Library/Frameworks/Python.framework/Versions/3.8/bin/python3

My machine is running macOS Catalina 10.15.7

Any ideas?


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Andrew Butterfield     Tel: +353-1-896-2517     Fax: +353-1-677-2204
Lero at TCD, Head of Software Foundations & Verification Research Group
School of Computer Science and Statistics,
Room G.39, O'Reilly Institute, Trinity College, University of Dublin
                         http://www.scss.tcd.ie/Andrew.Butterfield/
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