I just read this post, great info. But after digging a little I found out that you can use another method to do what you’re saying. You just have to create a file inside /etc/paths.d ; for instance if I’d like to append the mysql directory to the PATH I would do this:

1) Create the file /etc/paths.d/mysql like this:
sudo touch /etc/paths.d/mysql
2) Edit the file:
sudo vim /etc/paths.d/mysql
3) Put the path inside the file:
/usr/local/mysql/bin

I posted three steps so everyone knows what they’re doing, but you could do it all by just creating the file and filling it with the path needed in PATH.

I think this method works better because it is more ordered at the end and you would have a file for each path you want to create for every program that needs it.

Hope this helps.
Cheers. Felipe.