Lawrence Bottorff writes:
. . I'm sure if I install a ubuntu-debian package version of
(3.1.7) picolisp-repl will see that, i.e., it's hardwired
somewhere to look for a /usr/bin/ executable (pil or picolisp).
Not quite: the problem turns out to be that i've failed to make
use of the `picolisp-pil-executable` variable in `picolisp-repl`,
such that `pil` is only searched for in whatever paths have been
specified in Emacs' execution environment. Sorry! i'll fix that