Upgrade docker build images

build/linux.armv6hf/scutil

@@ -0,0 +1,48 @@
+#!/bin/dash
+# Various ShellCheck build utility functions
+
+# Generally set a ulimit to avoid QEmu using too much memory
+ulimit -v "$((10*1024*1024))"
+# If we happen to invoke or run under QEmu, make sure to follow execve.
+# This requires a patched QEmu.
+export QEMU_EXECVE=1
+
+# Retry a command until it succeeds
+# Usage: scutil retry 3 mycmd
+retry() {
+  n="$1"
+  ret=1
+  shift
+  while [ "$n" -gt 0 ]
+  do
+    "$@"
+    ret=$?
+    [ "$ret" = 0 ] && break
+    n=$((n-1))
+  done
+  return "$ret"
+}
+
+# Install all dependencies from a freeze file
+# Usage: scutil install_from_freeze /path/cabal.project.freeze cabal install
+install_from_freeze() {
+  linefeed=$(printf '\nx')
+  linefeed=${linefeed%x}
+  flags=$(
+    sed 's/constraints:/&\n /' "$1" |
+    grep -vw -e rts -e base |
+    sed -n -e 's/^  *\([^,]*\).*/\1/p' |
+    sed -e 's/any\.\([^ ]*\) ==\(.*\)/\1-\2/; te; s/.*/--constraint\n&/; :e')
+  shift
+  # shellcheck disable=SC2086
+  ( IFS=$linefeed; set -x; "$@" $flags )
+}
+
+# Run a command under emulation.
+# This assumes the correct emulator is named 'qemu' and the chroot is /chroot
+# Usage: scutil emu echo "Hello World"
+emu() {
+  chroot /chroot /bin/qemu /usr/bin/env "$@"
+}
+
+"$@"