dependencies not respecting `--cache-dir` flag

[zschreur]

Zig Version

0.14.1

Steps to Reproduce and Observed Behavior

Setup

Create two zig projects. Project A is a dependency of project B. Project A has a c_mod which is created from a addTranslateC call.

Project B has a module which depends on Project A. Project B uses the Project A import which depends on the translate C.

Error Steps

Run the following in Project B

zig build --cache-dir ./.other_cache

This produces the following error:

failed to check cache: './.other_cache/o/9518a4980110663bd82e69c066c1180d/index.zig' file_hash FileNotFound

It also creates the ./.zig-cache dir, which is where the generated file is.

If I run zig build without the --cache-dir flag, then this works as expected.

File overview

A)

> pwd
~/tmp/dep

>  ls
build.zig     build.zig.zon index.h       root.zig      zig-out

> cat build.zig
const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});
    const c_mod = b.addTranslateC(.{
        .root_source_file = b.path("index.h"),
        .target = target,
        .optimize = optimize,
    }).createModule();

    const mod = b.addModule("mymod", .{
        .root_source_file = b.path("root.zig"),
        .target = target,
        .optimize = optimize,
    });
    mod.addImport("c-import", c_mod);

    b.installArtifact(b.addLibrary(.{
        .name = "mylib",
        .root_module = mod,
    }));
}

> cat index.h
int add(int, int);

> cat root.zig
const c = @import("c-import");

pub fn add(a: i32, b: i32) i32 {
    return c.add(a, b);
}

B)

> pwd
~/tmp/proj

> ls
build.zig     build.zig.zon main.zig

> cat build.zig
const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

    const dep = b.dependency("dep", .{
        .target = target,
        .optimize = optimize,
    });
    const mod = b.createModule(.{
        .root_source_file = b.path("main.zig"),
        .target = target,
        .optimize = optimize,
    });
    mod.addImport("dep", dep.module("mymod"));

    const my_exe = b.addExecutable(.{
        .name = "main",
        .root_module = mod,
    });

    b.installArtifact(my_exe);
}

> cat main.zig
const std = @import("std");
const dep = @import("dep");

pub fn main() void {
    std.debug.print("{d}\n", .{dep.add(1, 2)});
}

Expected Behavior

The dependency uses ./.other-cache when it generates the translate-c file