User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 SeaMonkey/2.53.5.1
Hello.
$ a=abc
$ echo ${#a#a}
dash-0.5.11.3 produce:
3a
bash:
${#a#a}: bad substitution
Also, found incompatibility vs bash, may be is not bug:
for ${#*} bash eq $#, dash - s="$*" ${#s} :)
--w
vodz