It's not the first time I run into something like this :
$ ./pre-inst-env guix refresh emacs-haskell-mode [...]/gnu/packages/emacs-xyz.scm:2971:13: warning: 17.5 is greater than the latest known version of emacs-haskell-mode (16.1) This happens when the github interface has "releases" but stopped publishing them, even though some later tags exist. IMHO, the better developpement experience would be to use the latest tag when it's greater than the latest "release". -- Best regards, Nicolas Graves