I erased ALL the prevoius generations and still there are some elements
that "guix gc -d ..." cannot eliminate from the store because they turn out
to be "still alive"

Of course emacs-cider is not installed in the current generation

I don't understand.

Is there a way to let guix tell me what is still pointing to those ?

$ ls /gnu/store/ | grep emacs-cider
magg7sgr09yv4bc5pvhpgw4h7qslpa2s-emacs-cider-0.12.0.drv
myhz4ramjj089acxgj9bqjykwivqrlrj-emacs-cider-0.12.0-guile-builder
nswa3vzly4xd97b1ddz2n3312fd7nvaa-emacs-cider-0.12.0.tar.gz.drv
qkpfpc6ighlvq6x22ikh84vjpw6gxmji-emacs-cider-0.12.0-guile-builder
z00jb6ylnvlskaf0j1spbnirz6ck2q8y-emacs-cider-0.12.0.tar.gz.drv


guix gc -d /gnu/store/*-emacs-cider-0.12.0*
finding garbage collector roots...
guix gc: error: build failed: cannot delete path
`/gnu/store/magg7sgr09yv4bc5pvhpgw4h7qslpa2s-emacs-cider-0.12.0.drv' since
it is still alive