I have the same Issue – I get errors like “Could not create executables” and gcc fails..with: “Make-file not found” or “directory not found “errors..
It thought there is a problem with eh RetroPie-Setup-Build Folder but the source-Files and folders are all there and the rights are ok ..
The system and the retropie setup-scripts are up do date.. I have no clue why its not working anymore..
I found in another Thread that a 512 meg swap file is needed.. I will try that tonight..