Not only can I not reproduce this (please try to provide a detailed set of steps starting from make plain); but doing this makes no sense. ivy-sort-functions-alist is an alist mapping collection functions (i.e. :callers) to sorting functions:
ivy-sort-functions-alist is a variable defined in ‘ivy.el’.
Its value is
((read-file-name-internal . ivy-sort-file-function-default)
(t . ivy-string<))
An alist of sorting functions for each collection function.
Interactive functions that call completion fit in here as well.
Nil means no sorting, which is useful to turn off the sorting for
functions that have candidates in the natural buffer order, like
‘org-refile’ or ‘Man-goto-section’.
A list can be used to associate multiple sorting functions with a
collection. The car of the list is the current sort
function. This list can be rotated with ‘ivy-rotate-sort’.
The entry associated with t is used for all fall-through cases.
See also ‘ivy-sort-max-size’.
So, what you probably want is:
(const (lambda (xy)
(>0 (compare-strings x nilnil y nilnilt)))))