Here's a second version that actually works with multiple parameters,
is way more specific at telling you where badly-placed variables should be,
and also knows a heck of a lot more about existing variables.
#! /usr/bin/perl
# ex:ts=8 sw=4:
# $OpenBSD$
#
# Copyright (c) 2024 Marc Espie <espie@openbsd.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
use v5.36;

my $portsdir = $ENV{PORTSDIR} // '/usr/ports';
my $rc = 0;

# all variables we know that don't appear in Makefile.template
my @unreg = (qw(GH_ACCOUNT GH_COMMIT GH_PROJECT GH_TAGNAME V
    REVISION EPOCH REVISION-* EPOCH-* TEST_ENV
    FIX_EXTRACT_PERMISSIONS CFLAGS CXXFLAGS LDSTATIC
    PORTROACH MULTI_PACKAGES));

my $unreg = {map {($_, 1)} @unreg};

my @wantdash = (qw(BROKEN WANTLIB LIB_DEPENDS RUN_DEPENDS
    PERMIT_PACKAGE PKG_ARCH ONLY_FOR_ARCHS NOT_FOR_ARCHS));
my $wantdash = {map {($_, 1)} @wantdash};

sub read_order($file)
{
	my @list;
	open my $f, "<", $file or return;
	while (<$f>) {
		chomp;
		if (m/^([A-Z0-9_]+(:?\-[a-zA-Z0-9_]*)?)\s*\+?\=/) {
			push(@list, $1);
		} elsif (m/^\#\s*([A-Z0-9_]+(:?\-[a-zA-Z0-9_]*)?)\s*\+?\=/) {
			push(@list, $1);
		}
	}
	for my $i (@list) {
		$i =~ s/\-.*/\-\*/;
	}
	return \@list;
}

sub find_closest($e, $seen, $ref)
{
	my $f = 0;
	for my $i (@$ref) {
		if ($f == 0) {
			if ($i eq $e) {
				$f = 1;
			}
		} else {
			if ($seen->{$i}) {
				return " (should be before $i)";
			}
		}
	}
	return "";
}

# some variables don't appear with their '-' form in the template
sub fix_template($ref)
{
	my @list;
	for my $i (@$ref) {
		push(@list, $i);
		if ($wantdash->{$i}) {
			push(@list, "$i-*");
		}
	}
	return \@list;
}

my $ref = read_order("${portsdir}/infrastructure/templates/Makefile.template");
if (!defined $ref) {
	say STDERR "Couldn't read reference template";
	exit 2;
}

$ref = fix_template($ref);

my $all = {};
for my $i (@$ref) {
	$all->{$i} = 1;
}


for my $name (@ARGV) {
	my $port = read_order($name);
	if (!defined $port) {
		say STDERR "$name: Couldn't read";
		$rc = 2;
		next;
	}

	my @new = @$ref;

	my $old = {};
	my $seen = {};
	while (my $e = shift @$port) {
		$seen->{$e} = 1;
		if (!$all->{$e}) {
			if ($unreg->{$e}) {
				next;
			}
			say "$name: $e unknown";
			next;
		}
		if ($old->{$e}) {
			say "$name: $e late".
			    find_closest($e, $seen, $ref);
			$rc = 1;
			next;
		}
		while ($e ne $new[0]) {
			$old->{$new[0]} = 1;
			shift @new;
			if (@new == 0) {
				say "$name: $e ? (unknown error)";
				last;
				$rc = 1;
			}
		}
	}
}
exit $rc;

• port-var-check (3K)