Here is the story:

~/.profile - In this file you can also place environment variable assignments, since it gets executed automatically by the DisplayManager during the start-up process desktop session as well as by the login shell when one logs-in from the textual console.

(source)

1. solution: export the variables defined in .profile.

   
   
   

           export VAR1=foo




2. solution: put the variables in .bashrc, open a terminal and start QtCreator from command line. It should have the variables. Don't forget to export them:

   
   
   

   export VAR1=foo
   
   




3. solution: create a wrapper for starting your program, a small script that you run instead of running the program directly:

   
   
   

   #!/bin/bash
   
   
   
   export VAR1=foo
   
   program
   
   

   
   
   

   or

   
   
   

    #!/bin/bash
   
   
   
    VAR1=foo program
   
   




4. solution: edit the .desktop file used to launch the application by modifying the execute line to

   
   
   

    VAR1=foo program
   
   

   
   
   

   instead of

   
   
   

    program
   
   

   
   
   

   (haven't tested that, but it should work)




5. solution: change the environment. You are right in your comment that programs do get an environment, even if they do not read it from the .profile. The system-wide environment is in /etc/environment, but you can also set it per session, in a file in your home directory called .pam_environment. See here for more information. By the way, this page neatly explains what all the different files do and when to use which.

   
   
   

   However, I prefer solutions 1-3, because they change the environment of the program only, and not of the whole session.