Mac, for some idiotic reason is not case sensitive anymore:
$ echo 'You should see this assigned to abc' > abc ; echo 'and not only this printed twice' > ABC ; cat abc ABC
and not only this printed twice
and not only this printed twice
In order to work with source code I tried few things, such as USC-C SSD drive formated as case-sensitive, bu tit is too slow.
So I created a new case-sensitive APSF partition using DiskUtility.
$ cd /Volumes/REPO
REPO $ echo 'You should see this assigned to abc' > abc ; echo 'and not only this printed twice' > ABC ; cat abc ABC
You should see this assigned to abc
and not only this printed twice