Zig Version

0.12.0-dev.3161+377ecc6af

Steps to Reproduce and Observed Behavior

// repro.zig
const std = @import("std");
pub fn main() !void {
    var arena_state = std.heap.ArenaAllocator.init(std.heap.page_allocator);
    defer arena_state.deinit();
    const arena = arena_state.allocator();
    const args = try std.process.argsAlloc(arena);
    for (args, 0..) |arg, i| std.debug.print("args[{}]: \"{s}\"\n", .{ i, arg });
}

zig run .\repro.zig -- hello "" world

args[0]: "C:\...\repro.exe"
args[1]: "hello"
args[2]: "world"

Running the executable directly works.

C:\...\repro.exe hello "" world

args[0]: "C:\...\repro.exe"
args[1]: "hello"
args[2]: ""
args[3]: "world"

Invoking the executable directly from Zig using std.process.Child.init(&.{ repro_path, "hello", "", "world" }, arena) also works, so it doesn't appear to be a bug in the argv-to-command line serialization logic.

Appears to be a Windows-only bug, people on Discord helped me verify that it works correctly on Linux and macOS.

zig build run (where run is a Step.Run) is also affected.

Expected Behavior

The empty string is passed to the spawned process.