I picked the Git Clone URL from here, cloned the repo on my system, and the I run
makepkg -si in the repo's directory, which resulted in
dropbox-lnx.x86_64-102.4.431.tar.gz ... FAILED (unknown public key FC918B335044912E) ==> ERROR: One or more PGP signatures could not be verified!
From the FAQ section here, I read that this means I don't have the required public key, and that I need to go here, where I read that I should import the key, as described here; since there's no
public.key file in the repo, I copied the id from within the
PKGBUILD file and run
gpg --recv-keys 1C61A2656FB57B7E4DE0F4C1FC918B335044912E, which is also assumed the correct step to do in this question, where the answers don't deny it, but I got this error:
gpg: keyserver receive failed: Server indicated a failure
that the previous link does not mention; indeed, it mentions a similar error
gpg: keyserver receive failed: Connection refused (suggesting in that case to check your DNS servers or use others).