Automatically move stuff in lib64 to lib

pkgs/build-support/setup-hooks/move-lib64.sh

@@ -0,0 +1,21 @@
+# This setup hook, for each output, moves everything in $output/lib64
+# to $output/lib, and replaces $output/lib64 with a symlink to
+# $output/lib. The rationale is that lib64 directories are unnecessary
+# in Nix (since 32-bit and 64-bit builds of a package are in different
+# store paths anyway).
+
+fixupOutputHooks+=(_moveLib64)
+
+_moveLib64() {
+    if [ "$dontMoveLib64" = 1 ]; then return; fi
+    if [ ! -e "$prefix/lib64" -o -L "$prefix/lib64" ]; then return; fi
+    echo "moving $prefix/lib64/* to $prefix/lib"
+    mkdir -p $prefix/lib
+    shopt -s dotglob
+    for i in $prefix/lib64/*; do
+        mv "$i" $prefix/lib
+    done
+    shopt -u dotglob
+    rmdir $prefix/lib64
+    ln -s lib $prefix/lib64
+}

pkgs/build-support/setup-hooks/move-sbin.sh

@@ -6,7 +6,7 @@ fixupOutputHooks+=(_moveSbin)
 
 _moveSbin() {
     if [ "$dontMoveSbin" = 1 ]; then return; fi
-    if ! [ -e "$prefix/sbin" ]; then return; fi
+    if [ ! -e "$prefix/sbin" -o -L "$prefix/sbin" ]; then return; fi
     echo "moving $prefix/sbin/* to $prefix/bin"
     mkdir -p $prefix/bin
     shopt -s dotglob

pkgs/stdenv/generic/default.nix

@@ -45,6 +45,7 @@ let
       ../../build-support/setup-hooks/strip.sh
       ../../build-support/setup-hooks/patch-shebangs.sh
       ../../build-support/setup-hooks/move-sbin.sh
+      ../../build-support/setup-hooks/move-lib64.sh
       gcc
     ];