yb_release --package=cli fails (Mac OS)

[iSignal]

Running ./yb_release --package_name=cli on MacOS results in the following error:

We appear to be copying a binary file ysqlsh over to the destination which is a symlink. Might be a Python 3 issue.

2020-07-24 15:57:02,768 [mac_library_packager.py:361 INFO] Setting new path to @loader_path/../lib/libpgtypes.3.dylib for file /Users/sanketh/code2/yugabyte-db/build/yb_release_tmp_6b07ddfb-29c6-4947-97c7-7b93e9b7603a/yb_distribution/postgres/lib/libpgtypes.3.11.dylib
2020-07-24 15:57:02,780 [mac_library_packager.py:385 INFO] Absolute dependency /Users/sanketh/code2/yugabyte-db/build/release-clang-dynamic-ninja/postgres/lib/libpgtypes.3.dylib
2020-07-24 15:57:02,847 [mac_library_packager.py:361 INFO] Setting new path to @loader_path/../lib/libpq.5.dylib for file /Users/sanketh/code2/yugabyte-db/build/yb_release_tmp_6b07ddfb-29c6-4947-97c7-7b93e9b7603a/yb_distribution/postgres/lib/dblink.so
2020-07-24 15:57:02,858 [mac_library_packager.py:385 INFO] Absolute dependency /Users/sanketh/code2/yugabyte-db/build/release-clang-dynamic-ninja/postgres/lib/libpq.5.dylib
2020-07-24 15:57:03,456 [yb_release.py:236 INFO] Generating release distribution
Traceback (most recent call last):
  File "/Users/sanketh/code2/yugabyte-db/build-support/yb_release.py", line 289, in <module>
    main()
  File "/Users/sanketh/code2/yugabyte-db/build-support/yb_release.py", line 240, in main
    release_util.create_distribution(build_target)
  File "/Users/sanketh/code2/yugabyte-db/python/yb/release_util.py", line 126, in create_distribution
    copy_deep(file_path,
  File "/Users/sanketh/code2/yugabyte-db/python/yb/command_util.py", line 125, in copy_deep
    if os.path.getmtime(src) <= os.path.getmtime(dst):
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/genericpath.py", line 55, in getmtime
    return os.stat(filename).st_mtime
FileNotFoundError: [Errno 2] No such file or directory: '/Users/sanketh/code2/yugabyte-db/build/yb_release_tmp_6b07ddfb-29c6-4947-97c7-7b93e9b7603a/tmp_yb_distribution/bin/ysqlsh'```

cc: @WesleyW @jaki in case this was encountered recently.