remove unshare chroot style

replaces #1421. fixes #1403.

README.md

@@ -31,20 +31,6 @@ This utility requires these linux kernel options:
 This is the default method, and if your system does not support any of the required kernel
 options it will fail with `EINVAL (Invalid argument)`.
 
-#### unshare(1)
-
-This utility also requires `user_namespaces(7)` support and these linux kernel options:
-
-- CONFIG\_NAMESPACES
-- CONFIG\_IPC\_NS
-- CONFIG\_UTS\_NS
-- CONFIG\_USER\_NS
-
-To enable it:
-
-    $ cd void-packages
-    $ echo XBPS_CHROOT_CMD=unshare >> etc/conf
-
 #### xbps-uchroot(8)
 
 This utility requires these linux kernel options:

common/chroot-style/unshare.sh

@@ -1,31 +0,0 @@
-#!/bin/sh
-#
-# This chroot script uses unshare(1) with user_namespaces(7).
-#
-readonly MASTERDIR="$1"
-readonly DISTDIR="$2"
-readonly HOSTDIR="$3"
-readonly EXTRA_ARGS="$4"
-
-if ! command -v unshare >/dev/null 2>&1; then
-	exit 1
-fi
-
-if [ -z "$XBPS_IS_UNSHARED" ]; then
-	XBPS_IS_UNSHARED=1 exec unshare $EXTRA_ARGS -m -U -r -- "$0" "$@"
-	exit 1
-fi
-
-shift 4
-
-if [ -z "$MASTERDIR" -o -z "$DISTDIR" ]; then
-	echo "$0 MASTERDIR/DISTDIR not set"
-	exit 1
-fi
-
-for i in /dev /proc /sys; do
-	mount --rbind "$i" "$MASTERDIR/$i" || exit 1
-done
-mount --rbind "$DISTDIR" "$MASTERDIR/void-packages" || exit 1
-mount --rbind "$HOSTDIR" "$MASTERDIR/host" || exit 1
-exec chroot "$MASTERDIR" "$@"