2 files changed, 28 insertions, 14 deletions

diff --git a/flake.nix b/flake.nix
index 647d15b4a..25d025b1c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -163,16 +163,6 @@
           build-release-notes =
             final.buildPackages.callPackage ./maintainers/build-release-notes.nix { };
           clangbuildanalyzer = final.buildPackages.callPackage ./misc/clangbuildanalyzer.nix { };
-          boehmgc-nix = (final.boehmgc.override {
-            enableLargeConfig = true;
-          }).overrideAttrs (o: {
-            patches = (o.patches or [ ]) ++ [
-              ./boehmgc-coroutine-sp-fallback.diff
-
-              # https://github.com/ivmai/bdwgc/pull/586
-              ./boehmgc-traceable_allocator-public.diff
-            ];
-          });
 
           default-busybox-sandbox-shell = final.busybox.override {
             useMusl = true;
@@ -203,10 +193,13 @@
           nix = final.callPackage ./package.nix {
             inherit versionSuffix fileset;
             stdenv = currentStdenv;
-            boehmgc = final.boehmgc-nix;
             busybox-sandbox-shell = final.busybox-sandbox-shell or final.default-busybox-sandbox-shell;
             nix-doc = final.nix-doc;
           };
+
+          # Export the patched version of boehmgc that Lix uses into the overlay
+          # for consumers of this flake.
+          boehmgc-nix = final.nix.boehmgc-nix;
         };
 
     in {
@@ -268,7 +261,6 @@
             inherit versionSuffix fileset officialRelease buildUnreleasedNotes;
             inherit (pkgs) build-release-notes;
             internalApiDocs = true;
-            boehmgc = pkgs.boehmgc-nix;
             busybox-sandbox-shell = pkgs.busybox-sandbox-shell;
           };
         in
@@ -406,7 +398,6 @@
           let
             nix = pkgs.callPackage ./package.nix {
               inherit stdenv versionSuffix fileset;
-              boehmgc = pkgs.boehmgc-nix;
               busybox-sandbox-shell = pkgs.busybox-sandbox-shell or pkgs.default-busybox-sandbox;
               forDevShell = true;
             };
diff --git a/package.nix b/package.nix
index 6931726ad..8b1fb48ff 100644
--- a/package.nix
+++ b/package.nix
@@ -5,6 +5,11 @@
   autoconf-archive,
   autoreconfHook,
   aws-sdk-cpp,
+  # If the patched version of Boehm isn't passed, then patch it based off of
+  # pkgs.boehmgc. This allows `callPackage`ing this file without needing to
+  # to implement behavior that this package flat out doesn't build without
+  # anyway, but also allows easily overriding the patch logic.
+  boehmgc-nix ? __forDefaults.boehmgc-nix,
   boehmgc,
   nlohmann_json,
   bison,
@@ -63,6 +68,20 @@
   # stuff for argument defaults.
   __forDefaults ? {
     canRunInstalled = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
+
+    boehmgc-nix = (boehmgc.override {
+      enableLargeConfig = true;
+    }).overrideAttrs {
+      patches = [
+        # We do *not* include prev.patches (which doesn't exist in normal pkgs.boehmgc anyway)
+        # because if the caller of this package passed a patched boehm as `boehmgc` instead of
+        # `boehmgc-nix` then this will almost certainly have duplicate patches, which means
+        # the patches won't apply and we'll get a build failure.
+        ./boehmgc-coroutine-sp-fallback.diff
+        # https://github.com/ivmai/bdwgc/pull/586
+        ./boehmgc-traceable_allocator-public.diff
+      ];
+    };
   },
 }: let
   inherit (__forDefaults) canRunInstalled;
@@ -81,7 +100,7 @@
   # The internal API docs need these for the build, but if we're not building
   # Nix itself, then these don't need to be propagated.
   maybePropagatedInputs = [
-    boehmgc
+    boehmgc-nix
     nlohmann_json
   ];
 
@@ -324,4 +343,8 @@ in stdenv.mkDerivation (finalAttrs: {
   passthru.perl-bindings = pkgs.callPackage ./perl {
     inherit fileset stdenv buildWithMeson;
   };
+
+  # Export the patched version of boehmgc.
+  # flake.nix exports that into its overlay.
+  passthru.boehmgc-nix = __forDefaults.boehmgc-nix;
 })