detect failure to link libc when there is a dependency on libc

[dimenus]

using the following code in src/main.zig:

const std = @import("std");

pub usingnamespace @cImport({
    @cInclude("GLFW/glfw3.h");
});

pub fn main() anyerror!void {
    if (glfwInit() == 0) return error.GlfwInitFailed;
    std.debug.warn("All your base are belong to us.\n");
}

if I run
zig build-exe src/main.zig --library glfw --library-path /usr/lib

it fails with:

/home/ryan/repos/zgdb/src/main.zig:3:20: error: C import failed
pub usingnamespace @cImport({
                   ^
/home/ryan/repos/zgdb/src/main.zig:3:20: note: libc headers not available; compilation does not link against libc
pub usingnamespace @cImport({

but using zig build with this build.zig file causes SIGSEGV

const Builder = @import("std").build.Builder;

pub fn build(b: *Builder) void {
    const mode = b.standardReleaseOptions();
    const exe = b.addExecutable("zgdb", "src/main.zig");
    exe.setBuildMode(mode);
    exe.linkSystemLibrary("glfw");
    exe.setOutputDir(".");
    const run_cmd = exe.run();

    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);

    b.default_step.dependOn(&exe.step);
}

I recognize that the solution is to just include libc, but it seems like the behavior should be consistent, no?

edit (backtrace):

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0  0x0000000000000000 in ?? ()
#1  0x0000000000000000 in ?? ()

[distractedlambda]

I ran into the same issue earlier today, and when linking with GLFW at that! It doesn't seem to be an issue with zig build in particular; you can reproduce this with zig build-exe as long as you provide an -isystem argument that allows @cImport() to find the right headers. The segfault (at least for me) happens a few instructions into the body of whatever GLFW function I try to call, but I wasn't able to discern much more from that without debug symbols.