From c4b44b477144ffce2f6291f9dd13ffe36831db3d Mon Sep 17 00:00:00 2001
From: Kaidong Hu <hukaidonghkd@gmail.com>
Date: Wed, 28 Jan 2026 21:50:55 -0500
Subject: [PATCH 1/2] test: add docSupport test and add docSupport version
 check

There is a do-install-doc issue related to ruby version < 3.4.
This commit checks doc support for ruby version >= 3.4 and add guard
perventing docSupport be used in parallel build with early versions.

See: https://github.com/ruby/rubygems/issues/7580
---
 flake.nix               | 20 +++++++++++++++++++-
 ruby/package-fn.nix     |  7 ++++++-
 rubygems/package-fn.nix |  1 +
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/flake.nix b/flake.nix
index 43363cf..811436c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,7 +26,7 @@
           versionedPackageFnWithOverrides = { version, versionSource }:
             let pkg =
               pkgs.callPackage packageFn {
-                inherit version versionSource;
+                inherit version versionSource versionComparison;
               };
             in
             applyOverrides {
@@ -191,6 +191,24 @@
                   ruby -e 'require "foobar"; say' > $out
                 '';
               };
+            }) // (lib.optionalAttrs (with versionComparison rubyVersion; greaterOrEqualTo "3.4") {
+              "${rubyName}-docSupport" = {
+                nativeBuildInputs = [
+                  (ruby.override { docSupport = true; })
+                ];
+                command = ''
+                  ri Array > $out
+                '';
+              };
+            }) // (lib.optionalAttrs (with versionComparison rubyVersion; lessThan "3.4") {
+              "${rubyName}-docSupport-noParallel" = {
+                nativeBuildInputs = [
+                  (ruby.override { docSupport = true; parallelBuild = false; })
+                ];
+                command = ''
+                  ri Array > $out
+                '';
+              };
             })
           ) rubyPackages;
 
diff --git a/ruby/package-fn.nix b/ruby/package-fn.nix
index c91cd46..b83ba4b 100644
--- a/ruby/package-fn.nix
+++ b/ruby/package-fn.nix
@@ -1,5 +1,6 @@
 { version
 , versionSource
+, versionComparison
 , libDir ? "${(import ./parse-version.nix version).majMin}.0"
 , rubygems ? null
 , stdenv
@@ -25,6 +26,7 @@
 , bundler
 , bundix
 , removeReferencesTo
+, parallelBuild ? true
 , useRailsExpress ? true
 , zlibSupport ? true
 , opensslSupport ? true
@@ -87,7 +89,7 @@ let
       propagatedBuildInputs =
         (op jemallocSupport jemalloc);
 
-      enableParallelBuilding = true;
+      enableParallelBuilding = parallelBuild;
 
       postPatch = ''
         ${opString (rubygems != null) ''
@@ -195,4 +197,7 @@ let
       };
     };
 in
+# There's a known race condition when building with docs enabled before Ruby 3.4.0
+# Building documents requires parallelBuild to be false in those versions
+assert docSupport -> (with versionComparison version; greaterOrEqualTo "3.4.0" || !parallelBuild);
 self
diff --git a/rubygems/package-fn.nix b/rubygems/package-fn.nix
index 97d46c6..a7fea1d 100644
--- a/rubygems/package-fn.nix
+++ b/rubygems/package-fn.nix
@@ -3,6 +3,7 @@
 , stdenv
 , fetchurl
 , fetchpatch
+, ...
 }:
 stdenv.mkDerivation {
   pname = "rubygems";

From 17a24748a83eaff13a8373e8bed269c79d77f964 Mon Sep 17 00:00:00 2001
From: Kaidong Hu <hukaidonghkd@gmail.com>
Date: Sat, 11 Apr 2026 14:37:19 -0400
Subject: [PATCH 2/2] Fix docSupport build failure in Nix sandbox

rdoc tries to create XDG_DATA_DIR (defaulting to $HOME/.local/share) during the build, but $HOME is read-only in the Nix sandbox.

This adds a writable $HOME during the preConfigure phase, and applies the
same fix to the docSupport tests in flake.nix.

See: https://github.com/bobvanderlinden/nixpkgs-ruby/pull/221

Co-Authored-By: Sander <hey@sandydoo.me>
---
 flake.nix           | 4 ++--
 ruby/package-fn.nix | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/flake.nix b/flake.nix
index 811436c..824d143 100644
--- a/flake.nix
+++ b/flake.nix
@@ -197,7 +197,7 @@
                   (ruby.override { docSupport = true; })
                 ];
                 command = ''
-                  ri Array > $out
+                  HOME=$TMPDIR ri Array > $out
                 '';
               };
             }) // (lib.optionalAttrs (with versionComparison rubyVersion; lessThan "3.4") {
@@ -206,7 +206,7 @@
                   (ruby.override { docSupport = true; parallelBuild = false; })
                 ];
                 command = ''
-                  ri Array > $out
+                  HOME=$TMPDIR ri Array > $out
                 '';
               };
             })
diff --git a/ruby/package-fn.nix b/ruby/package-fn.nix
index b83ba4b..cee84ec 100644
--- a/ruby/package-fn.nix
+++ b/ruby/package-fn.nix
@@ -109,6 +109,11 @@ let
 
       preConfigure = ''
         sed -i configure -e 's/;; #(/\n;;/g'
+        ${opString docSupport ''
+          # rdoc creates XDG_DATA_DIR (defaulting to $HOME/.local/share) even if
+          # it's not going to be used.
+          export HOME=$TMPDIR
+        ''}
       '';
 
       configureFlags =