if rootcint fails, its output files are removed:
Warning: Error occurred during reading source files
Warning: Error occurred during dictionary source generation
!!!Removing graf3d/gl/src/G__GL.cxx graf3d/gl/src/G__GL.h !!!
Is there an option to keep them for debugging?
[quote]Is there an option to keep them for debugging?[/quote]No, there is not … and it is unlikely that you would learn much by looking at them. Instead you might want to increase the debugging output by adding the -T -t option to rootcint, which will output what cint parses at the time it parses it, usually giving a better indication of the source of the problem.