Context:
- zig version: 0.15.2
- OS: NixOS, Ubuntu
I’ve been trying to understand how to get the -fsanitize-thread option working and not having a great deal of success.
I have a small example program here that definitely has a race that helgrind happily confirms:
const std = @import(“std”);
var bank_account: i32 = 200;
pub fn main() !void {
var creditor = try std.Thread.spawn(.{}, credit, .{});
var debitor = try std.Thread.spawn(.{}, debit, .{});
creditor.join();
debitor.join();
std.debug.print(“balance: ‘{d}’\n”, .{bank_account});
}
pub fn credit() void {
var i: usize = 0;
while (i < 1000) : (i += 1) {
var balance = bank_account;
balance += 20;
bank_account = balance;
}
}
pub fn debit() void {
var i: usize = 0;
while (i < 1000) : (i += 1) {
var balance = bank_account;
balance -= 20;
bank_account = balance;
}
}
When I build this code, I use:
zig build-exe -fsanitize-thread threads.zig
However, when I execute the resulting binary, I’m not seeing any output from TSAN, even when increasing the verbosity.
TSAN_OPTIONS=“verbosity=3” ./threads
Unfortunately, I haven’t been able to find a lot of information online regarding the usage or behavior of this build option. If anybody could offer some suggestions or pointers, I’d greatly appreciate it! 
Testing now, each option independently achieves the desired behavior, and it makes sense why.