Here is the error:
[python2-2.7.15.p0] Copying package files from temporary location /Applications/SageMath-8.7.app/Contents/Resources/sage/local/var/tmp/sage/build/python2-2.7.15.p0/inst to /Applications/SageMath-8.7.app/Contents/Resources/sage/local
[python2-2.7.15.p0] cp: symlink: python-2.7.pc: File exists
[python2-2.7.15.p0] cp: symlink: python2.pc: File exists
[python2-2.7.15.p0] ************************************************************************
[python2-2.7.15.p0] Error copying files for python2-2.7.15.p0.
[python2-2.7.15.p0] ************************************************************************
[python2-2.7.15.p0] Please email sage-devel
[python2-2.7.15.p0] explaining the problem and including the log file
[python2-2.7.15.p0] /Applications/SageMath-8.7.app/Contents/Resources/sage/logs/pkgs/python2-2.7.15.p0.log
[python2-2.7.15.p0] Describe your computer, operating system, etc.
[python2-2.7.15.p0] ************************************************************************
make[1]: *** [/Applications/SageMath-8.7.app/Contents/Resources/sage/local/var/lib/sage/installed/python2-2.7.15.p0] Error 1
real 2m38.586s
user 1m47.897s
sys 0m39.865s
***************************************************************
Error building Sage.
The following package(s) may have failed to build (not necessarily during this run of 'make python2'):
* package: python2-2.7.15.p0
log file: /Applications/SageMath-8.7.app/Contents/Resources/sage/logs/pkgs/python2-2.7.15.p0.log
build directory: /Applications/SageMath-8.7.app/Contents/Resources/sage/local/var/tmp/sage/build/python2-2.7.15.p0
The build directory may contain configuration files and other potentially
helpful information. WARNING: if you now run 'make' again, the build
directory will, by default, be deleted. Set the environment variable
SAGE_KEEP_BUILT_SPKGS to 'yes' to prevent this.
make: *** [python2] Error 1
It looks like there is an error with a symlink - cp: symlink: python-2.7.pc: File exists
