Pkg-config can't find gobject

Help
1

Hi,

I installed these packages:

pkg-config
glib
glibc
gobject-introspection
dbus
dbus-glib
gtk4
gtk3
vala

With a sample vala code:

class Demo.HelloWorld : GLib.Object {
    public static int main(string[] args) {
        stdout.printf("Hello, World\n");
        return 0;
    }
}

Command:

$ valac sample.vala

I get this error:

Package gobject-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gobject-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gobject-2.0' found
error: pkg-config exited with status 256
Compilation failed: 1 error(s), 0 warning(s)

I tried different ways like --pkg and etc but nothing worked.

When I try to get list of known packages by pkg-config, it returns nothing.

$ pkg-config --list-all

I searched in the internet and forum but nothing found to fix my problem. I’m pretty sure I missed something in my local system.

2

Some packages have multiple outputs and you will need to use the correct one. gobject-2.0.pc is in glib.dev instead of just glib.

I’ve found nix-index with its nix-locate tool to be invaluable for this kind of stuff. It finds exactly which derivation produces certain files in its output. Since updating the index takes forever, I also recommend using nix-index-database which does this nicely with the regular system updates.

In your case, it would produce:

$ nix-locate gobject-2.0.pc
(virtualgl.out)                                     365 r /nix/store/kn0wlcvwkgxlzssxgyy6am453dwmf2ik-glib-2.78.1-dev/lib/pkgconfig/gobject-2.0.pc
vlang.out                                           304 r /nix/store/rhk41k4mxy2q2q3nqpfzf4n5rg96hpf5-vlang-0.4.3/lib/vlib/v/pkgconfig/test_samples/gobject-2.0.pc
remarkable-toolchain.out                            287 r /nix/store/jm8lh0xlyj1lqghd5hd8y4ih39ynizla-remarkable-toolchain-3.1.2/sysroots/cortexa9hf-neon-remarkable-linux-gnueabi/usr/lib/pkgconfig/gobject-2.0.pc
remarkable2-toolchain.out                           287 r /nix/store/v8id91gp55sz64vnwg0q1lv281hc5271-remarkable2-toolchain-3.1.2/sysroots/cortexa7hf-neon-remarkable-linux-gnueabi/usr/lib/pkgconfig/gobject-2.0.pc
glib.dev                                            365 r /nix/store/xc5casr35bpf24dj0sp3jjwh76mkslg4-glib-2.78.1-dev/lib/pkgconfig/gobject-2.0.pc

Making it quite obvious where to look.

1 Like
3

What is the value of your PKG_CONFIG_PATH environment variable? On my system, it’s empty. I needed to add the installed location of those libraries before pkg-config --list-all would produce anything.

export PKG_CONFIG_PATH=/run/current-system/sw/lib/pkgconfig:$PKG_CONFIG_PATH

Another method, which may be helpful, is to use nix-shell and a shell.nix file like this:

{ pkgs ? import <nixpkgs> {} }:

with pkgs;

mkShell {
  name = "sample-vala";

  nativeBuildInputs = [
    vala
    pkg-config
  ];

  buildInputs = [
    glib
    gobject-introspection
    dbus-glib
    gtk4
    gtk3
  ];
}
1 Like
4

Don’t install libraries through nix-env or systemPackages, use nix-shell instead. See FAQ/I installed a library but my compiler is not finding it. Why? - NixOS Wiki for details

1 Like
5

I’d like the idea of nix-index. I didn’t know that. It’s very useful. Thanks for mentioning that!
I’d tried with glib.dev but still the same issue.

6

Thank you!
It works!