generate ld.so.cache in build instead of post-install

APKBUILD

@@ -7,17 +7,14 @@ pkgdesc="GNU C Library compatibility layer"
 arch="x86_64"
 url="https://github.com/gliderlabs/alpine-glibc"
 license="GPL"
-install="$pkgname.post-install"
-source="http://mirrors.kernel.org/archlinux/core/os/x86_64/glibc-${pkgver}-${pkgrel}-${arch}.pkg.tar.xz
-ld.so.conf"
+source="http://mirrors.kernel.org/archlinux/core/os/x86_64/glibc-${pkgver}-${pkgrel}-${arch}.pkg.tar.xz"
 subpackages="$pkgname-bin"
 
 package() {
   mkdir -p "$pkgdir"/usr/glibc
   mkdir "$pkgdir"/etc
   mkdir "$pkgdir"/lib64
   cp -a "$srcdir"/usr "$pkgdir"/usr/glibc/usr
-  cp -La "$srcdir"/ld.so.conf "$pkgdir"/etc/
   rm -rf "$pkgdir"/usr/glibc/usr/lib/systemd \
     "$pkgdir"/usr/glibc/usr/lib/gconv \
     "$pkgdir"/usr/glibc/usr/lib/locale \
@@ -28,15 +25,13 @@ package() {
     "$pkgdir"/usr/glibc/usr/bin/* \
     "$pkgdir"/usr/glibc/usr/include \
     "$pkgdir"/usr/glibc/usr/share
-  cp -a "$srcdir"/usr/bin/ldconfig "$pkgdir"/usr/glibc/usr/bin/
+  "$srcdir"/usr/bin/ldconfig -r "$pkgdir" -C /etc/ld.so.cache /usr/glibc/usr/lib
   ln -s /usr/glibc/usr/lib/ld-linux-x86-64.so.2 ${pkgdir}/lib64/ld-linux-x86-64.so.2
 }
 
 bin() {
   mkdir -p "$subpkgdir"/usr/glibc/usr/bin
   cp -a "$srcdir"/usr/bin/* "$subpkgdir"/usr/glibc/usr/bin/
-  rm "$subpkgdir"/usr/glibc/usr/bin/ldconfig
 }
 
-md5sums="cd2bef93120db7401bd7a4451e97dab4  glibc-2.21-2-x86_64.pkg.tar.xz
-fda27293b95f89c7a61a0d379d1c3bde  ld.so.conf"
+md5sums="cd2bef93120db7401bd7a4451e97dab4  glibc-2.21-2-x86_64.pkg.tar.xz"