Hi again, everyone.

When trying to build Boost 1.69.0 after having placed my installation of Python 3.7.1 above the one of Python 2.7.15, I got the error mentioned in the title of this email.  It says at the end, 

"

...failed updating 4 targets...
...updated 2381 targets...

"

The project-config.jam file I used is attached to this message.