I am quite troubled as this shouldn\'t be causing me such a headache. I\'ve downloaded the most recent Eclipse Indigo and all CDT C++ plugins for MAC OS X 10.7.1/<
I solved a similar problem with Eclipse by creating a "Launch Configuration". I am using the Indigo release of Eclipse on OSX Lion with CDT (C/C++ dev environment). I found the option to create a new launch configuration in Project->Properties->Run/Debug Settings.
I encountered this problem after creating and building an empty "Hello World Ansi C Autotools Project". The build process created a working executable as src/a.out. I could run a.out successfully from the terminal but Eclipse did not understand that this was an executable for my project until I created a launch configuration pointing to it. Once I did that I was able to run a.out as usual using the green run button.
I am using Eclipse Oxygen and the following fixed my problem:
Right-click on your project and go to properties. Navigate to C/C++ Build > Tool Chain Editor and select MacOSX GCC in the Current toolchain, and Apply and Close.
Build your project with CMD+B and then run it.
I was having the same problem, so I fiddled around a littpe bit and found out that if I clicked on the "profile" button (green play icon with a little clock under it), to the right of the "run" button, my program would Run the next time I clicked on the Run button.
I actually dont know what that did, but it allowed me to run the code.
if anybody knows why this helped, and whether it is an actual solution or not dont hesitate to relpy!