When upgrading from kwin-4.9.5, kde-base/kwin-4.10.1-r2 fails with the misleading errors: ../../../kwin-4.10.1/kwin/libkwineffects/kwinglutils_funcs.h:33:37: error: variable or field 'glResolveFunctions' declared void ../../../kwin-4.10.1/kwin/libkwineffects/kwinglutils_funcs.h 33:37: error: 'OpenGLPlatformInterface' was not declared in this scope (Actually the compilation should fail with all USE-flag combinations, so I wonder how kde-4.10.1 could have become stable...) The error comes from kwinglutils_funcs.h containing the line #include <kwinglobals.h> which apparently reads /usr/include/kwinglobals.h from the previous install of kwin - in kwin-4.9.5 that file does not contain the definition of the enum OpenGLPlatformInterface, only the new file kwin/libkwineffects/kwinglobals.h does. (Actually, also some other [presumably buggy] #include lines of the same type are contained in kwin/libkwineffects/kwinglutils_funcs.h, but at least concerning compilation with kde-4.9.5 installed they make no harm.) Patching that #include line(s) is probably not a good idea, since kwinglutils_funcs.h will be installed. Moving the old /usr/include/kwinglobals.h out of the way before compiling and then emerging twice works (to be safe, I have set CCACHE_RECACHE=1 the second time), but this is not a nice solution for users, of course. The better solution would probably be to fix the order of include directories, but I am not familiar enough with the build system to suggest a corresponding patch quickly. (Moreover, I am not motivated, since the above hackish workaround worked for me...)
Is that to say that it failed with ccache, but worked without?
(In reply to comment #1) > Is that to say that it failed with ccache, but worked without? No, ccache has nothing to do with the bug. I wrote this only in case somebody wants to repeat my hack, uses ccache, and wants to be completely on the safe side (probably, it is not even necessary to compile a second time). (I considered the bug as major, because startkde depends on kwin, and so a kde-based system becomes practically broken in the middle of an upgrade.)
I updated last week my netbook, works for me. kde-stable team had done the same. I guess its ccache related and ccache is evil as we all known.
(In reply to comment #3) > I guess its ccache related and ccache is evil as we all known. It is definitely not ccache related. I have analyzed and desribed the cause, please read it: The header file kwinglobals.h is read from the installed version instead of from the new version, because there is #include <...> instead of #include "..." in kwinglutils_funcs.h (which, however, must not just be patched into kwinglutils_funcs.h, because the latter is installed and thus probably needs the #include <...> for other programs using that file). It presumable works if for whatever reason you had already a newer version of kwin than 4.9.5. Maybe it also does not occur with certain useflags combinations (if e.g. #include "kwinglobals.h" occurs before the include of kwinglutils_funcs.h in a compilation unit there is no problem - I did not check carefully in which combinations this is the case, but obviously not in all). Maybe the problem was fixed in kwin-4.10.2 which now is stable. Of course, I did not downgrade just to test it.
Just for the record: My USE for kdewin are opengl -aqua -debug -gles