nix-prefetch-zip does not exist

[DamienCassou]

$ cabal run melpa2nix -- --threads 4 --melpa ../melpa --stable --work /tmp/melpa --output /tmp/melpa-stable.nix shell-switcher
Preprocessing library emacs2nix-0.1.0.0...
In-place registering emacs2nix-0.1.0.0...
Preprocessing executable 'melpa2nix' for emacs2nix-0.1.0.0...
Running melpa2nix...
PackageException "shell-switcher" (ProcessFailed "nix-prefetch-zip" ["--url","https://github.com/DamienCassou/shell-switcher/archive/2c5575ae859a82041a4bacd1793b844bfc24c34f.tar.gz","--name","shell-switcher-2c5575ae859a82041a4bacd1793b844bfc24c34f-src"] nix-prefetch-zip: runInteractiveProcess: runInteractiveProcess: exec: does not exist (No such file or directory))

[DamienCassou]

this happens with and without merging #13

[ttuegel]

The POSIX error message is strangely worded, but it actually means that exec can't find the file it's looking for, not that exec itself doesn't exist.

This happens because you need to either run one of the provided shell scripts, or run melpa2nix from inside a Nix shell with nix-shell -A env.