Install error: missing rational.py

[Colin Campbell]

Pulled from master this morning. Compiled without apparent error. 
Install choked as below. Deleted /build, re-ran autogen.sh, mkdir build, 
cd build, ../configure and re-compiled, again without apparent error.

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colin@Sherlock build]$ sudo make install
[sudo] password for colin:
Traceback (most recent call last):
  File "/home/colin/lilypond-git/build/scripts/build/out/install", line 
77, in <module>
    shutil.copy2 (f, dest)
  File "/usr/lib64/python3.7/shutil.py", line 266, in copy2
    copyfile(src, dst, follow_symlinks=follow_symlinks)
  File "/usr/lib64/python3.7/shutil.py", line 120, in copyfile
    with open(src, 'rb') as fsrc:
FileNotFoundError: [Errno 2] No such file or directory: 'rational.py'
make[1]: *** 
[/home/colin/lilypond-git/build/../stepmake/stepmake/install-out-targets.make:9: 
local-install-outfiles] Error 1
make: *** 
[/home/colin/lilypond-git/build/../stepmake/stepmake/toplevel-targets.make:27: 
install] Error 2

***************************************

Curiously, rational.py appears in several locations on my machine:

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colin@Sherlock build]$ locate rational.py
/home/colin/lilypond-git/build/python/out/rational.py
/home/colin/lilypond-git/python/rational.py
/usr/local/share/lilypond/2.21.0/python/rational.py
/usr/local/share/lilypond/2.21.0/python/rational.pyc
/usr/share/lilypond/2.19.84/python/rational.py
/usr/share/lilypond/2.19.84/python/rational.pyc
*****************************************


ISTM I compiled a week or so ago without error, so I'm open to guidance 
from the collected wisdom.


Cheers,

Colin


--
There is nothing so useless as doing efficiently that which should not 
be done at all.
- Peter F. Drucker, 1909 - 2005