mkExtraUtils: use upstream's method.

overlay/lib/extra-utils.nix

@@ -2,6 +2,7 @@
   runCommandCC
   , nukeReferences
   , glibc
+  , writeShellScriptBin
   , buildPackages
 }:
 
@@ -23,10 +24,55 @@ let
       ${if set ? extraCommand then set.extraCommand else ""}
     '';
   install_packages = concat(map (install_package) packages);
+
+  # A utility for enumerating the shared-library dependencies of a program
+  findLibs = writeShellScriptBin "find-libs" ''
+    set -euo pipefail
+    declare -A seen
+    declare -a left
+    patchelf="${buildPackages.patchelf}/bin/patchelf"
+    function add_needed {
+      rpath="$($patchelf --print-rpath $1)"
+      dir="$(dirname $1)"
+      for lib in $($patchelf --print-needed $1); do
+        left+=("$lib" "$rpath" "$dir")
+      done
+    }
+    add_needed $1
+    while [ ''${#left[@]} -ne 0 ]; do
+      next=''${left[0]}
+      rpath=''${left[1]}
+      ORIGIN=''${left[2]}
+      left=("''${left[@]:3}")
+      if [ -z ''${seen[$next]+x} ]; then
+        seen[$next]=1
+        # Ignore the dynamic linker which for some reason appears as a DT_NEEDED of glibc but isn't in glibc's RPATH.
+        case "$next" in
+          ld*.so.?) continue;;
+        esac
+        IFS=: read -ra paths <<< $rpath
+        res=
+        for path in "''${paths[@]}"; do
+          path=$(eval "echo $path")
+          if [ -f "$path/$next" ]; then
+              res="$path/$next"
+              echo "$res"
+              add_needed "$res"
+              break
+          fi
+        done
+        if [ -z "$res" ]; then
+          echo "Couldn't satisfy dependency $next" >&2
+          exit 1
+        fi
+      fi
+    done
+  '';
+
 in
 runCommandCC "extra-utils-${name}"
   {
-    nativeBuildInputs = [ nukeReferences buildPackages.glibc.bin ];
+    nativeBuildInputs = [ nukeReferences ];
     allowedReferences = [ "out" ];
   }
   ''
@@ -41,12 +87,11 @@ runCommandCC "extra-utils-${name}"
 
     # Copy ld manually since it isn't detected correctly
     cp -pv ${glibc.out}/lib/ld*.so.? $out/lib
+
     # Copy all of the needed libraries
     find $out/bin $out/lib -type f | while read BIN; do
       echo "Copying libs for executable $BIN"
-      LDD="$(ldd $BIN)" || continue
-      LIBS="$(echo "$LDD" | awk '{print $3}' | sed '/^$/d')"
-      for LIB in $LIBS; do
+      for LIB in $(${findLibs}/bin/find-libs $BIN); do
         TGT="$out/lib/$(basename $LIB)"
         if [ ! -f "$TGT" ]; then
           SRC="$(readlink -e $LIB)"

overlay/overlay.nix

@@ -19,6 +19,7 @@ in
         runCommandCC
         glibc
         buildPackages
+        writeShellScriptBin
       ;
       inherit (self.buildPackages)
         nukeReferences