From 9bcd91ba09dbe6d7cb93b2774a77596d914563ca Mon Sep 17 00:00:00 2001
From: Thomas Watson <twatson52@icloud.com>
Date: Sat, 6 Apr 2024 15:11:48 -0500
Subject: [PATCH] build-fhsenv-bubblewrap: reference 32-bit binaries only if
 multiArch

Fixes issues using bubblewrap'd fhsenvs in scenarios where i686 is not
supported (such as Rosetta 2 emulation in a Linux VM on Apple Silicon).
---
 .../build-fhsenv-bubblewrap/buildFHSEnv.nix         | 13 ++++++-------
 .../build-fhsenv-bubblewrap/default.nix             |  2 +-
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/pkgs/build-support/build-fhsenv-bubblewrap/buildFHSEnv.nix b/pkgs/build-support/build-fhsenv-bubblewrap/buildFHSEnv.nix
index 81813473a8db..2ab7847926e2 100644
--- a/pkgs/build-support/build-fhsenv-bubblewrap/buildFHSEnv.nix
+++ b/pkgs/build-support/build-fhsenv-bubblewrap/buildFHSEnv.nix
@@ -40,12 +40,11 @@ let
   isMultiBuild = multiArch && stdenv.system == "x86_64-linux";
   isTargetBuild = !isMultiBuild;
 
-  # list of packages (usually programs) which are only be installed for the
-  # host's architecture
+  # list of packages (usually programs) which match the host's architecture
+  # (which includes stuff from multiPkgs)
   targetPaths = targetPkgs pkgs ++ (if multiPkgs == null then [] else multiPkgs pkgs);
 
-  # list of packages which are installed for both x86 and x86_64 on x86_64
-  # systems
+  # list of packages which are for x86 (only multiPkgs, only for x86_64 hosts)
   multiPaths = multiPkgs pkgsi686Linux;
 
   # base packages of the chroot
@@ -76,8 +75,8 @@ let
   ];
 
   ldconfig = writeShellScriptBin "ldconfig" ''
-    # due to a glibc bug, 64-bit ldconfig complains about patchelf'd 32-bit libraries, so we're using 32-bit ldconfig
-    exec ${if stdenv.system == "x86_64-linux" then pkgsi686Linux.glibc.bin else pkgs.glibc.bin}/bin/ldconfig -f /etc/ld.so.conf -C /etc/ld.so.cache "$@"
+    # due to a glibc bug, 64-bit ldconfig complains about patchelf'd 32-bit libraries, so we use 32-bit ldconfig when we have them
+    exec ${if isMultiBuild then pkgsi686Linux.glibc.bin else pkgs.glibc.bin}/bin/ldconfig -f /etc/ld.so.conf -C /etc/ld.so.cache "$@"
   '';
 
   etcProfile = writeText "profile" ''
@@ -251,7 +250,7 @@ let
 
 in runCommandLocal "${name}-fhs" {
   passthru = {
-    inherit args baseTargetPaths targetPaths baseMultiPaths ldconfig;
+    inherit args baseTargetPaths targetPaths baseMultiPaths ldconfig isMultiBuild;
   };
 } ''
   mkdir -p $out
diff --git a/pkgs/build-support/build-fhsenv-bubblewrap/default.nix b/pkgs/build-support/build-fhsenv-bubblewrap/default.nix
index e06fb51dd4b6..c30a4dfb7ea3 100644
--- a/pkgs/build-support/build-fhsenv-bubblewrap/default.nix
+++ b/pkgs/build-support/build-fhsenv-bubblewrap/default.nix
@@ -252,7 +252,7 @@ let
       --symlink /etc/ld.so.cache ${glibc}/etc/ld.so.cache \
       --ro-bind ${glibc}/etc/rpc ${glibc}/etc/rpc \
       --remount-ro ${glibc}/etc \
-  '' + optionalString (stdenv.isx86_64 && stdenv.isLinux) (indentLines ''
+  '' + optionalString fhsenv.isMultiBuild (indentLines ''
       --tmpfs ${pkgsi686Linux.glibc}/etc \
       --symlink /etc/ld.so.conf ${pkgsi686Linux.glibc}/etc/ld.so.conf \
       --symlink /etc/ld.so.cache ${pkgsi686Linux.glibc}/etc/ld.so.cache \