Quick hack to collect licenses of dependencies using stack

licenses.sh

#!/bin/bash
# This is a quick hack using stack to list dependencies and then
# copying their licenses from the locations in which it stores them.
# It tries various possible filenames in the store first, then tries
# the global location for system packages.  It will miss out licenses
# for parts of the local project, the "rts" package (but that's okay,
# because it is covered by the license for "base"), and will
# (silently) exclude licenses for underlying C libraries.

LOCAL_PATH=.stack-work/install/x86_64-linux/lts-9.0/8.0.2/doc/
STORE_PATH=~/.stack/snapshots/x86_64-linux/lts-9.0/8.0.2/doc/
GLOBAL_PATH=/opt/ghc/8.0.2/share/doc/ghc-8.0.2/html/libraries
DIR=licenses
LIST=stack-dependencies.txt

mkdir -p $DIR
stack list-dependencies --test | tr ' ' '-' > $LIST
for P in `cat $LIST`
do
    cp $LOCAL_PATH/$P/LICENSE $DIR/$P.txt 2>/dev/null \
        || cp `ls $STORE_PATH/$P/{LICENSE,LICENCE,LICENSE.txt,license.txt,licence.txt,BSD3,COPYING} 2>/dev/null | head -n 1` $DIR/$P.txt 2>/dev/null \
        || cp $GLOBAL_PATH/$P/LICENSE $DIR/$P.txt 2>/dev/null \
        || echo "Missing license for $P"
done