Add a prepare function to the PKGBUILD to fetch the required crates:

prepare() {
  cd $_pkgname
  cargo fetch --locked --target host-tuple
}

BUILD currently fails.

error: there is no argument named `loc`
   --> src/response.rs:423:32
    |
423 |                 format!("{} => {loc}", self.url())
    |                                ^^^^^

error[E0277]: expected a `FnMut<(char,)>` closure, found `[char; 37]`
  --> src/nlp/utils.rs:44:9
   |
43 |       text.replace(
   |            ------- required by a bound introduced by this call
44 | /         [
45 | |             '!', '\\', '"', '#', '$', '%', '&', '(', ')', '*', '+', ':', ';', '<', '=', '>', '?',
46 | |             '@', '[', ']', '^', '{', '}', '|', '~', ',', '\'', '“', '”', '’', '‘', '’', '‘', '/',
47 | |             '–', '—', '.',
48 | |         ],
   | |_________^ expected an `FnMut<(char,)>` closure, found `[char; 37]`
   |
   = help: the trait `FnMut<(char,)>` is not implemented for `[char; 37]`
   = note: required because of the requirements on the impl of `Pattern<'_>` for `[char; 37]`

For more information about this error, try `rustc --explain E0277`.
error: could not compile `feroxbuster` due to 2 previous errors
warning: build failed, waiting for other jobs to finish...
error: build failed
==> ERROR: A failure occurred in build().
    Aborting...
 -> error making: feroxbuster-git

@spikecodes is this package still maintained by you or has it been orphaned? it would be helpful if the pkgver fix and the shell completions could be added to the PKGBUILD file.

Install the shell completions as well?

install -Dm644 "${_pkgname}/shell_completions/${_pkgname}.fish" "$pkgdir/usr/share/fish/vendor_completions.d/${_pkgname}.fish"
install -Dm644 "${_pkgname}/shell_completions/_${_pkgname}"     "$pkgdir/usr/share/zsh/site-functions/_${_pkgname}"