error: NoSpaceLeft on a program built with the x86_64 backend

[amarz45]

Zig Version

0.14.0-dev.3462+edabcf619

Steps to Reproduce and Observed Behavior

The following program runs fine when built with LLVM enabled but gives an error when using the x86_64 backend:

const std = @import("std");

const linux = std.os.linux;

const statfs = extern struct {
    f_type:    __fsword_t,
    f_bsize:   __fsword_t,
    f_blocks:  blkcnt_t,
    f_bfree:   blkcnt_t,
    f_bavail:  blkcnt_t,

    f_files:   fsfilcnt_t,
    f_ffree:   fsfilcnt_t,
    f_fsid:    fsid_t,
    f_namelen: __fsword_t,
    f_frsize:  __fsword_t,
    f_flags:   __fsword_t,

    const __fsword_t = isize;
    const blkcnt_t = linux.blkcnt_t;
    const fsfilcnt_t = u64;
    const fsid_t = linux.fsid_t;
};

pub fn main() ! void {
    var buf: [1024]u8 = undefined;
    std.debug.print("{s}\n", .{try get_storage(&buf)});
}

fn get_storage(buf: []u8) ! []const u8 {
    var stat: statfs = undefined;
    if (linux.syscall2(.statfs, @intFromPtr("/"), @intFromPtr(&stat)) != 0)
        std.process.exit(1);

    const total_bytes = stat.f_blocks * stat.f_bsize;
    return std.fmt.bufPrint(buf, "{} B", .{total_bytes});
}

When adding .use_llvm = false in the executable options of build.zig and trying to run the program, I get the following output:

error: NoSpaceLeft
/usr/local/lib/zig/std/io/fixed_buffer_stream.zig:63:46: 0x1053db5 in write (std.zig)
            if (self.pos >= self.buffer.len) return error.NoSpaceLeft;
                                             ^
/usr/local/lib/zig/std/io.zig:348:13: 0x103463f in typeErasedWriteFn (std.zig)
            return writeFn(ptr.*, bytes);
            ^
/usr/local/lib/zig/std/io/Writer.zig:13:5: 0x1055af4 in write (std.zig)
    return self.writeFn(self.context, bytes);
    ^
/usr/local/lib/zig/std/io/Writer.zig:19:18: 0x1034c43 in writeAll (std.zig)
        index += try self.write(bytes[index..]);
                 ^
/usr/local/lib/zig/std/fmt.zig:1068:9: 0x1055679 in formatBuf__anon_6771 (std.zig)
        try writer.writeAll(buf);
        ^
/usr/local/lib/zig/std/fmt.zig:1246:5: 0x1153735 in formatInt__anon_23546 (std.zig)
    return formatBuf(buf[index..], options, writer);
    ^
/usr/local/lib/zig/std/fmt.zig:780:5: 0x1153ada in formatIntValue__anon_23542 (std.zig)
    return formatInt(int_value, base, case, options, writer);
    ^
/usr/local/lib/zig/std/fmt.zig:729:32: 0x1153ba4 in formatValue__anon_23512 (std.zig)
        .int, .comptime_int => return formatIntValue(value, fmt, options, writer),
                               ^
/usr/local/lib/zig/std/fmt.zig:520:13: 0x1152a84 in formatType__anon_23402 (std.zig)
            return formatValue(value, actual_fmt, options, writer);
            ^
/usr/local/lib/zig/std/fmt.zig:193:9: 0x115102a in format__anon_23384 (std.zig)
        try formatType(
        ^
/usr/local/lib/zig/std/fmt.zig:1805:30: 0x11512df in bufPrint__anon_23254 (std.zig)
        error.NoSpaceLeft => return error.NoSpaceLeft,
                             ^
/home/amaral/source/new/src/main.zig:27:32: 0x114f941 in main (main.zig)
    std.debug.print("{s}\n", .{try get_storage(&buf)});

Expected Behavior

Here is an example of expected output:

254985371648 B