getting env vars failing | Zig Programming Language | Page 1

kindred locust Jul 19, 2023, 5:30 PM

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I am trying to fetch an env var on my M1 machine and no matter whether I use the std.os or std.proccess methods the env var is always not found (even when it is set). Is this maybe a mac issue?

spark edge Jul 19, 2023, 6:01 PM

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what is the code that fails?

kindred locust Jul 19, 2023, 6:06 PM

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spark edge what is the code that fails?

const rpc = try getEnvVarOwned(allocator, "mainnet_rpc");

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and mainnet_rpc is set an an env var. Can confirm with an echo $mainnet_rpc

chrome star Jul 19, 2023, 9:19 PM

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I guess the obvious questions are:

Are you sure you have the case correct?
Are you sure that the zig program is running in a context that has the environment variable set?

alpine mantle Jul 19, 2023, 9:32 PM

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its possible this is a result of not linking libc. could you try again with libc linked?

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there's an issue for this https://github.com/ziglang/zig/issues/4524

kindred locust Jul 19, 2023, 9:32 PM

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I am running using zig build test if that helps

alpine mantle Jul 19, 2023, 9:33 PM

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so in your build.zig, i think you'll need something like

test_exe.linkLibC();

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did you try this? i'm not saying its a solution, just trying to help find the problem.

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maybe try running this

// /tmp/tmp.zig
const std = @import("std");

// pub fn main() !void {
test {
    const foo = try std.process.getEnvVarOwned(std.heap.page_allocator, "FOO");
    std.debug.print("foo={s}\n", .{foo});
}

$ FOO="BAR" zig test /tmp/tmp.zig
Test [1/1] test_0... foo=BAR
All 1 tests passed.

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and if that fails, try

$ FOO="BAR" zig test /tmp/tmp.zig -lc

kindred locust Jul 19, 2023, 9:54 PM

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Hmm this actually works even without -lc

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I wonder if its since I am doing it from zig build test (which I need to use since my project has deps that are imported using the package manager and setup in the build file)

alpine mantle Jul 19, 2023, 10:00 PM

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is it returning an error or just not printing anything?

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another thing to check, are the tests just getting cached? you can see if its getting cached w/ $ zig build test --summary all

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and to prevent it in your build.zig

const run_unit_tests = b.addRunArtifact(unit_tests);
run_unit_tests.has_side_effects = true;

kindred locust Jul 19, 2023, 11:20 PM

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It returns the variable not found error. It's also not a cache issue as I made changes to trigger a rebuild, but I didn't know I could do this in the build file which is cool.

#getting env vars failing