Created attachment 499684 [details] Emerge log with USE="sparse" When using the sparse flag, adolc should be linked with ColPack. Such relation is defined on the use flags, but the patch "${FILESDIR}"/${PN}-2.5.0-no-colpack.patch always disables ColPack on the configuration process. The result is that config.h do not contains the flag HAVE_LIBCOLPACK and errors like fprintf(DIAG_OUT, "ADOL-C error: function %s can only be used if linked with ColPack\n", __FUNCTION__); are returned when using the library. Deleting the 2.5.0-no-colpack.patch creates a library that works correctly. On the attached emerge log, not that -lColPack is not used when linking.