$info =~ m!\A100644 blob ([a-f0-9]{40})\t!s or die "not blob: $info";
my $oid = $1;
my $msg = _cat_blob($r, $w, $oid) or die "BUG: cat-blob $1 failed";
$info =~ m!\A100644 blob ([a-f0-9]{40})\t!s or die "not blob: $info";
my $oid = $1;
my $msg = _cat_blob($r, $w, $oid) or die "BUG: cat-blob $1 failed";