Make missing cpanmods message friendlier.

Scrapecore needs ~/.genpkg/var/cpanmods data to exist.
When it is missing try to give a friendlier error message.

1 files changed, 3 insertions, 0 deletions

diff --git a/preps/perl.d/scrapecore b/preps/perl.d/scrapecore
index 25f5c80..c8bdac5 100755
--- a/preps/perl.d/scrapecore
+++ b/preps/perl.d/scrapecore
@@ -208,6 +208,9 @@ sub coreonly
 	my %mods = map { @$_ } @_;
 	my $var = $ENV{'PKGVAR'} || "$ENV{'HOME'}/.genpkg/var";
 	my $path = "$var/cpanmods";
+	unless(-f $path){
+		die "$0: $path is missing. Generate it with fetchcpan.\n";
+	}
 	open(my $if, '<', $path) or die("open $path failed: $!");
 
 	my @dists;