[+cc bug-gnulib, see below for a reason] Minimal reproducer of the regression:
$ cat foo.bash echo "$BASH_VERSION" declare -A hash echo ${hash[a/b]} echo $? $ /bin/bash foo.bash 4.2.45(1)-release 0 $ ~/bleeding/bin/bash foo.bash 4.3.0(1)-alpha foo.bash: line 3: a/b: division by 0 (error token is "b") 1 Notice that the new behaviour breaks the gnulib-tool script (that's how I noticed this regression). Regards, Stefano