Odd error when using BoundedArray at comptime, but not runtime due to @memcpy

[euclidianAce]

Zig Version

0.11.0-dev.3031+f40539e5d

Steps to Reproduce and Observed Behavior

run the following tmp.zig

pub fn main() anyerror!void {
    std.log.info("{}", .{array});
}

const array = blk: {
    var b = std.BoundedArray(u8, 8){};
    b.appendSlice("hello") catch unreachable;
    break :blk b;
};

const std = @import("std");

which produces the following error:

$ zig run tmp.zig
zig-0.11.0-dev/lib/std/bounded_array.zig:248:13: error: element access of non-indexable type 'u8'
            @memcpy(self.slice()[old_len..][0..items.len], items);
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
zig-0.11.0-dev/lib/std/bounded_array.zig:240:43: note: called from here
            self.appendSliceAssumeCapacity(items);
            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
tmp.zig:7:18: note: called from here
    b.appendSlice("hello") catch unreachable;
    ~~~~~~~~~~~~~^~~~~~~~~

but moving the comptime block inside of main is fine:

pub fn main() anyerror!void {
    const array = blk: {
        var b = std.BoundedArray(u8, 8){};
        b.appendSlice("hello") catch unreachable;
        break :blk b;
    };

    std.log.info("{}", .{array});
}

const std = @import("std");

$ zig run tmp.zig
info: bounded_array.BoundedArrayAligned(u8,1,8){ .buffer = { 104, 101, 108, 108, 111, 0, 0, 0 }, .len = 5 }

Expected Behavior

The code at compile time to produce the correct value without erroring

[jacobly0]

Unrelated to the bug, but b.appendSliceAssumeCapacity("hello"); is the usual way to assert that it can't overflow.

Reduction:

const S = struct {
    buffer: [8]u8 = undefined,
    fn set(self: *S, items: []const u8) void {
        @memcpy(self.buffer[0..items.len], items);
    }
};

comptime {
    var s = S{};
    s.set("hello");
}

[Vexu]

Duplicate of #15634

[Vexu]

Sorry, not a duplicate, didn't notice the slice.