bug#59503: 28.2.50; cannot set --mandir when installing

[daanturo]

Despite having set --prefix and/or --mandir to a writable directory in
my $HOME, `make install` always throws me this:

/usr/bin/mkdir: cannot create directory ‘/usr/local/share/man/man1’: Permission 
denied

Currently on commit 0636e106

Configure flags:

./configure --prefix=$HOME/opt/emacs-28.2.50
--program-transform-name='s/\(ctags\)/\1.emacs/' --with-json
--with-libsystemd --with-modules --with-native-compilation
--with-sound=alsa --without-compress-install

-- 
Daanturo.