RFC: Recent macos lacks nroff and man needs a full path

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

Is $ENV{'PWD'} reliable enough here?

diff --git a/Util/helpfiles b/Util/helpfiles
index 9e837fe2d..eed9b6d0e 100755
--- a/Util/helpfiles
+++ b/Util/helpfiles
@@ -54,7 +54,7 @@
 $mantmp = $destdir . '/man.tmp';
 $coltmpbase = 'col.tmp';
 $coltmp = $destdir . '/' . $coltmpbase;
-$args = "$manfile >$mantmp";
+$args = "$ENV{'PWD'}/$manfile >$mantmp";
 unlink($mantmp);
 &Info('attempting man ', $args);
 if(system('man ' . $args) || !(-s $mantmp)) {