std.Build.Step.ConfigHeader: cmakedefine in comments are not ignored

[mikastiv]

Zig Version

0.14.0-dev.2178+bd7dda0c5

Steps to Reproduce and Observed Behavior

std.Build.Step.ConfigHeader tries to render commented cmake defines.

test.cmake.h:

/* !!! FIXME: for later cmakedefine MY_VAR @MY_VAR@ */

build.zig:

    // ...
    const header = b.addConfigHeader(.{
        .style = .{ .cmake = b.path("test.cmake.h") }
    }, .{});
    exe.addConfigHeader(header);
    // ...

error: ...\test.cmake.h:1: unable to substitute variable: error: MissingValue
error: HeaderConfigFailed

Expected Behavior

Defines in comments should be ignored