How to edit pkgbuild in yay

[shmu26]

I did

yay --editmenu --nodiffmenu --save

and now, yay lets me edit pkgbuild, which I need, because a certain package I want to install has the wrong url, as noted in the comments.
https://aur.archlinux.org/packages/fax4cups/
The correct url is
http://mirror.transip.net/gentoo/gentoo/distfiles/fax4CUPS-1.29.tar.gz
I tried it, and it works.
But the pkgbuild still fails with 404 error, and I can’t figure out why.

shmuel@shmuel-arch ~ [1]> yay fax4cups
1 aur/fax4cups 1.29-1 (+1 0.00) 
    Fax backend for CUPS supporting hylafax hylafaxplus mgetty-fax efax capisuite
==> Packages to install (eg: 1 2 3, 1-3 or ^4)
==> 1
:: Checking for conflicts...
:: Checking for inner conflicts...
[Aur:1]  fax4cups-1.29-1

  1 fax4cups                         (Build Files Exist)
==> Packages to cleanBuild?
==> [N]one [A]ll [Ab]ort [I]nstalled [No]tInstalled or (1 2 3, 1-3, ^4)
==> a
:: Deleting (1/1): /home/shmuel/.cache/yay/fax4cups
:: (1/1) Downloaded PKGBUILD: fax4cups
:: (1/1) Parsing SRCINFO: fax4cups
  1 fax4cups                         (Build Files Exist)
==> PKGBUILDs to edit?
==> [N]one [A]ll [Ab]ort [I]nstalled [No]tInstalled or (1 2 3, 1-3, ^4)
==> a

 -> $EDITOR is not set
 -> Add $EDITOR or $VISUAL to your environment variables
==> Edit PKGBUILD with?
==> nano

==> Proceed with install? [Y/n] 
==> Making package: fax4cups 1.29-1 (Thu 26 Aug 2021 11:59:27 AM IDT)
==> Retrieving sources...
  -> Downloading fax4CUPS-1.29.tar.gz...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (22) The requested URL returned error: 404
==> ERROR: Failure while downloading http://mirror.transip.net/gentoo/gentoo/distfiles/fax4CUPS/fax4CUPS-1.29.tar.gz
    Aborting...
 -> error downloading sources: fax4cups 
         context: exit status 1 
         

==> Making package: fax4cups 1.29-1 (Thu 26 Aug 2021 11:59:28 AM IDT)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
  -> Downloading fax4CUPS-1.29.tar.gz...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--    0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (22) The requested URL returned error: 404
==> ERROR: Failure while downloading http://mirror.transip.net/gentoo/gentoo/distfiles/fax4CUPS/fax4CUPS-1.29.tar.gz
    Aborting...
 -> error making: fax4cups

[Kresimir]

Why don’t you just download it and build the package manually?

See:

How to Install Apps from AUR

makepkg is a script that creates a foreign (i.e. non-repo) package, which can be installed using pacman -U. Before we can make a package, we need to have both base-devel and git packages installed: sudo pacman -S base-devel git --needed On EndeavourOS, these should already be preinstalled. Depending on the specific package, we may also need other programs, like compilers and build systems. These are called “make dependencies”. Typically, making a package from the AUR involves the following …

[Dev0ut]

Try another mirror for fax4CUPS-1.29.tar.gz

EDIT : https://www.joonet.de/sources/fax4cups/oldsrc/fax4CUPS-1.29.tar.gz

[shmu26]

I tried that already. It is supposed to set up a CUPS printer, and apparently, that works differently on Arch than on other distros, I got a lot of errors. I thought maybe yay could do it better.
This is the line I edited:

url='http://mirror.transip.net/gentoo/distfiles/fax4CUPS'

[shmu26]

I just saw your EDIT I will try it