https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117737
Bug ID: 117737 Summary: GCC: cannot build anymore under CYGWIN, INCLUDE_MEMORY is missing Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: regression Assignee: unassigned at gcc dot gnu.org Reporter: carlo.bramix at libero dot it Target Milestone: --- I tried to build the sources of GCC under CYGWIN for making MinGW cross compiler, but I cannot do it anymore. After a while, I got this error on the console: In file included from ../../gcc/gcc/config/i386/host-cygwin.cc:25: ../../gcc/gcc/diagnostic.h:29:3: error: #error "You must define INCLUDE_MEMORY before including system.h to use diagnostic.h" 29 | # error "You must define INCLUDE_MEMORY before including system.h to use diagnostic.h" | ^~~~~ I don't know exactly what's going on, but adding INCLUDE_MEMORY before including headers inside host-cygwin.cc fixed the issue. I'm using the latest git sources, updated to commit 8d7f2d5.