From 5e67dd4292f9abec4e505b318906f4941165459f Mon Sep 17 00:00:00 2001
From: Graham Knop <haarg@haarg.org>
Date: Mon, 28 Aug 2023 07:39:04 +0200
Subject: [PATCH] delay loading PICA modules in PICA::Schema to work around
 circular dependencies (#137)

The various modules in this dist have circular dependencies between
them. This would result in PICA::Patch failing to import subs from
PICA::Schema, because the sub and exporting was not set up yet by the
time it would try to import. Perl would ignore the call to import when
the method didn't exist.

Delay loading the other PICA modules until after all parsing has been
completed and exporting is set up.

Future versions of perl are intending to throw errors when passing
arguments to an undefined import method, which causes test failures.
This also helped reveal the broken import.
---
 lib/PICA/Schema.pm | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/PICA/Schema.pm b/lib/PICA/Schema.pm
index 7e4a158..c417e91 100644
--- a/lib/PICA/Schema.pm
+++ b/lib/PICA/Schema.pm
@@ -6,13 +6,14 @@ our $VERSION = '2.06';
 use Scalar::Util qw(reftype);
 use Storable     qw(dclone);
 use List::Util   qw(pairs);
-use PICA::Data;
-use PICA::Error;
 
 use Exporter 'import';
 our @EXPORT_OK
     = qw(field_identifier check_value clean_pica parse_subfield_schedule);
 
+require PICA::Data;
+require PICA::Error;
+
 sub new {
     my ($class, $schema) = @_;
     cleanup_field_schedule($schema->{fields});