[gizmo686]

Is the trick here the "-trigraphs" flag, or the fact that you are showing us test.c but compiling test2.c? Both approaches seem like they should work.

[cdcarter]

It's the trigraph ??/ which translates to a \.

[gizmo686]

The trigraph appears in the file "test.c". If you look at the compilation command, you will see that that is not the file that is actually compiled.

[cbsmith]

If you compile "test.c" you will see that that isn't relevant issue.