fn allocPrintCmd2(arena: Allocator, opt_cwd: ?[]const u8, opt_env: ?*const std.process.EnvMap, argv: []const []const u8) Allocator.Error![]u8
arena: Allocator,
opt_cwd: ?[]const u8,
opt_env: ?*const std.process.EnvMap,
argv: []const []const u8,