debug: add module

This one is fairly similar to `environment.enableDebugInfo`[1] (hence
the name). It ensures that the `debug`-output of packages defined in
`home.packages` is installed if available and ensures that
`gdb`/`elfutils` find those symbols by adding
`~/.nix-profile/lib/debug` to the `NIX_DEBUG_INFO_DIRS`[2] variable.

[1] https://github.com/NixOS/nixpkgs/blob/release-19.09/nixos/modules/config/debug-info.nix
[2] https://github.com/NixOS/nixpkgs/blob/release-19.09/pkgs/development/tools/misc/gdb/debug-info-from-env.patch

PR #1040

1 files changed, 26 insertions, 0 deletions

diff --git a/modules/misc/debug.nix b/modules/misc/debug.nix
new file mode 100644
index 00000000000..d27d496b423
--- /dev/null
+++ b/modules/misc/debug.nix
@@ -0,0 +1,26 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+{
+  options.home = {
+    enableDebugInfo = mkEnableOption "" // {
+      description = ''
+        Some Nix-packages provide debug symbols for
+        <command>gdb</command> in the <literal>debug</literal>-output.
+        This option ensures that those are automatically fetched from
+        the binary cache if available and <command>gdb</command> is
+        configured to find those symbols.
+      '';
+    };
+  };
+
+  config = mkIf config.home.enableDebugInfo {
+    home.extraOutputsToInstall = [ "debug" ];
+
+    home.sessionVariables = {
+      NIX_DEBUG_INFO_DIRS =
+        "$NIX_DEBUG_INFO_DIRS\${NIX_DEBUG_INFO_DIRS:+:}${config.home.profileDirectory}/lib/debug";
+    };
+  };
+}