Build system hits unreachable on unknown CPU name

[Vexu]

Zig Version

0.12.0-dev.2640+b3aed4e2c

Steps to Reproduce and Observed Behavior

$ zig build -Dcpu=foo
thread 28134 panic: attempt to use null value
/home/vexu/Documents/zig/zig/lib/std/Build.zig:1294:31: 0x11438b5 in parseTargetQuery (build)
                diags.cpu_name.?, @tagName(diags.arch.?),
                              ^
/home/vexu/Documents/zig/zig/lib/std/Build.zig:1358:45: 0x11d330f in standardTargetOptionsQueryOnly (build)
    const selected_target = parseTargetQuery(.{
                                            ^
/home/vexu/Documents/zig/zig/lib/std/Build.zig:1283:51: 0x11721a0 in standardTargetOptions (build)
    const query = b.standardTargetOptionsQueryOnly(args);
                                                  ^
/home/vexu/Documents/zig/zig/build.zig:23:41: 0x116cd94 in build (build)
        break :t b.standardTargetOptions(.{ .default_target = default_target });
                                        ^
/home/vexu/Documents/zig/zig/lib/std/Build.zig:1983:43: 0x1145764 in runBuild__anon_8986 (build)
        .ErrorUnion => try build_zig.build(b),
                                          ^
/home/vexu/Documents/zig/zig/lib/build_runner.zig:310:29: 0x11416ea in main (build)
        try builder.runBuild(root);
                            ^
/home/vexu/Documents/zig/zig/lib/std/start.zig:585:37: 0x112a825 in posixCallMainAndExit (build)
            const result = root.main() catch |err| {
                                    ^
/home/vexu/Documents/zig/zig/lib/std/start.zig:253:5: 0x112a311 in _start (build)
    asm volatile (switch (native_arch) {
    ^
???:?:?: 0x9 in ??? (???)
Unwind information for `???:0x9` was not available, trace may be incomplete

error: the following build command crashed:
/home/vexu/Documents/zig/zig/zig-cache/o/1ffdb7443ec588f22ef0862f8b0f5229/build /home/vexu/Documents/zig/zig/build-dev/bin/zig /home/vexu/Documents/zig/zig /home/vexu/Documents/zig/zig/zig-cache /home/vexu/.cache/zig --seed 0xe95999e9 -Z48c581864273b215 -Dno-bin -Dcpu=foo

Expected Behavior

The error being printed properly.

[xdBronch]

same thing happens for unknown OS

➜ zig build -Dtarget=native-bar
thread 318747 panic: attempt to use null value
/home/user/zig/lib/std/Build.zig:1320:30: 0x10c5e82 in parseTargetQuery (build)
            , .{diags.os_name.?});
                             ^
/home/user/zig/lib/std/Build.zig:1358:45: 0x1133baf in standardTargetOptionsQueryOnly (build)
    const selected_target = parseTargetQuery(.{
                                            ^
/home/user/zig/lib/std/Build.zig:1283:51: 0x10e57e0 in standardTargetOptions (build)
    const query = b.standardTargetOptionsQueryOnly(args);
                                                  ^
/home/user/zaka/build.zig:4:43: 0x10e51f4 in build (build)
    const target = b.standardTargetOptions(.{});
                                          ^
/home/user/zig/lib/std/Build.zig:1983:43: 0x10c77c0 in runBuild__anon_8960 (build)
        .ErrorUnion => try build_zig.build(b),
                                          ^
/home/user/zig/lib/build_runner.zig:310:29: 0x10c374a in main (build)
        try builder.runBuild(root);
                            ^
/home/user/zig/lib/std/start.zig:585:37: 0x10ac885 in posixCallMainAndExit (build)
            const result = root.main() catch |err| {
                                    ^
/home/user/zig/lib/std/start.zig:253:5: 0x10ac371 in _start (build)
    asm volatile (switch (native_arch) {
    ^