Today I realized that the `./pre-inst-env guix` commands supposed to start instantly, just like the regular guix commands. If it takes 2-3 minutes to initialize and it prints lines like this:

```
;;; note: source file /home/user/[...]/guix/guix/ui.scm
;;; newer than compiled /home/user/[...]/guix/guix/ui.go
```

then do the `make clean-go` and `make` steps as suggested in the manual, and it will be fast again (until the .scm files remain the same):

https://guix.gnu.org/manual/1.5.0/en/html_node/Building-from-Git.html

#guix