/usr/share/cli-common/gac-install is in cli-common 0.9+nmu1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | #!/bin/bash
# Make sure the GAC file exists
if [ ! -x /usr/share/cli-common/runtimes.d/$1 ]; then
    echo ! Cannot install GAC $1
    exit 1
fi
# Make some useful noise
#echo "Installing packages in $1"
for file in /usr/share/cli-common/packages.d/*.installcligac
do
  if [ -f $file ]; then
      /usr/share/cli-common/gac-package-install \
	  $(basename $file .installcligac) \
	  $1
  fi
done
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