If we fail to find a requested namespace, we should tell the user
which ones we know about, since those were already fetched. This
allows users to fetch all namespaces by specifying a dummy namespace,
failing, then copying the list of namespaces in the config.

Eventually, we should have a flag that allows fetching all namespaces
automatically.

Reviewed-by: Antoine Beaupré <redacted>
Signed-off-by: Antoine Beaupré <redacted>
---
 contrib/mw-to-git/git-remote-mediawiki.perl | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/contrib/mw-to-git/git-remote-mediawiki.perl b/contrib/mw-to-git/git-remote-mediawiki.perl
index a1d783789..e7616e1a2 100755
--- a/contrib/mw-to-git/git-remote-mediawiki.perl
+++ b/contrib/mw-to-git/git-remote-mediawiki.perl

@@ -1334,7 +1334,9 @@ sub get_mw_namespace_id {
 	my $id;
 
 	if (!defined $ns) {
-		print {*STDERR} "No such namespace ${name} on MediaWiki.\n";
+		my @namespaces = sort keys %namespace_id;
+		for (@namespaces) { s/ /_/g; }
+		print {*STDERR} "No such namespace ${name} on MediaWiki, known namespaces: @namespaces\n";
 		$ns = {is_namespace => 0};
 		$namespace_id{$name} = $ns;
 	}

-- 
2.11.0