When site.addpackage(), running on a posix (e.g. 
cygwin or linux) system, reads lines from a .pth file that 
have '\r\n' line terminators, the carriage return character 
interferes with both the import operation and the 
directory appending operation.

The situation can arise, for example, when .pth files 
reside on a network directory that is shared between 
Windows and Posix installations and accessed by 
python interpreters running in both environments.

Suggested change:
replace site.py line 146:
        dir = f.readline()
with
        dir = f.readline().rstrip()
This change also eliminates the need for removing the 
newline at lines 154-155