Fix Emacs not recognizing environment variables

Problem

If you start Emacs in GUI form on Linux, then your Emacs might not be able to read the environment variables that set in .bashrc file. This is due to the fact that the system login shell is not the same as the interactive shell. The login shell does not read the .bashrc file by default, instead, it reads the .bash_profile file which normally locates in your $HOME directory. And desktops like Gnome use the login shell to boot.

Solution

So, here is a simple solution, move your environment variables configuration to .bash_profile, and add the following line in .bashrc:

source ~/.bash_profile

Reboot the system. When you come back, everything should works fine.

Test

Following command in Emacs should display the PATH variable.

M-x getenv PATH <ret>