From 38d8aab4d283efe2f43c7e18411f6df7e1c2d04b Mon Sep 17 00:00:00 2001
From: Michael Holmes <i.am@ceph3.us>
Date: Mon, 5 Apr 2021 22:54:04 +0100
Subject: [PATCH] std/build: fix ?[:0]const u8 build options

As per the other string types, `?[:0]const u8` needs its own case
as otherwise it will raise an error about using `{}` with slices.

There's no reasonable workaround for this, as you would have to
either discount the use of the empty string value or manually
rework the string to be sentinel-terminated at runtime. It's
useful for passing build options to code making use of C libraries
that make strong use of sentinel-terminated arrays for strings.
---
 lib/std/build.zig | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/std/build.zig b/lib/std/build.zig
index 825312755f..a652de9c12 100644
--- a/lib/std/build.zig
+++ b/lib/std/build.zig
@@ -1939,6 +1939,15 @@ pub const LibExeObjStep = struct {
                 out.print("pub const {}: []const u8 = \"{}\";\n", .{ std.zig.fmtId(name), std.zig.fmtEscapes(value) }) catch unreachable;
                 return;
             },
+            ?[:0]const u8 => {
+                out.print("pub const {}: ?[:0]const u8 = ", .{std.zig.fmtId(name)}) catch unreachable;
+                if (value) |payload| {
+                    out.print("\"{}\";\n", .{std.zig.fmtEscapes(payload)}) catch unreachable;
+                } else {
+                    out.writeAll("null;\n") catch unreachable;
+                }
+                return;
+            },
             ?[]const u8 => {
                 out.print("pub const {}: ?[]const u8 = ", .{std.zig.fmtId(name)}) catch unreachable;
                 if (value) |payload| {