Sometimes I need to figure out which gem update broke my build.

bundle-bisect.sh

#! /bin/sh
#

GEMFILE=Gemfile.lock

[ $# -lt 1 ] && { echo "Usage: $0 cmd" >&2; return 1; }

[ -r $GEMFILE ] || { echo "Cannot find $GEMFILE" >&2; return 1; }

cmd="$@"
eval $cmd || { echo "\`$*\` fails!" >&2; return 1; }

gems=`cat $GEMFILE | sed -n '/specs\:/,/^$/p' | sed 1d | awk '{print $1}' | sort | uniq`

num_gems=`echo $gems | wc -w`
[ $num_gems -gt 5 ] && { echo; echo "$(tput setaf 3)You have $num_gems gems; this may take a while!$(tput sgr 0)"; echo; }

for gem in $gems; do
	echo "Trying $gem ..."
	bundle update $gem && {
		eval $cmd || bad_gems="$bad_gems $gem"
	}
	git checkout $GEMFILE
done

if [ z$bad_gems -eq z ]; then
	echo "$(tput setaf 2)All of your gems update ok$(tput sgr 0)"
else
	echo "$(tput setaf 1)The following gems fail: $bad_gems$(tput sgr 0)"
	return 2
fi