https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104289
--- Comment #2 from eric.pouech at orange dot fr --- Thx for looking into it. For sake of completeness, clang supports it flawlessly. [eric]$ clang -fdiagnostics-parseable-fixits -c b2.c b2.c:9:28: warning: format specifies type 'int' but the argument has type 'long' [-Wformat] "long line: %d\n", l); ~~ ^ %ld fix-it:"b2.c":{9:21-9:23}:"%ld" b2.c:3:26: note: expanded from macro 'foo' #define foo(x...) printf(x); ^ 1 warning generated.