`s,` undefined between versions 0.7.9_20201231 and 0.7.9_20210422?

After updating version 0.7.9_20201231 to 0.7.9_20210422, a program of
mine failed because `s,` is not defined.

I searched the sources of Gforth, and `s,` is still in <prims2x.fs>,
which has not changed. As a temporary solution, I copied its definition
into my program, but then it crashed with "Invalid memory address".

Some days later I have compiled Gforth again from the latest sources
just in case, but no difference.

Finally I'm using 0.7.9_20201231, and everything works fine.

It seems something has changed between those versions.

-- 
Marcos Cruz
http://programandala.net