Better (to make sure that $ep is defined before we try a substitution on it):
Index: config/init/install.pm =================================================================== --- config/init/install.pm (revision 21171) +++ config/init/install.pm (working copy) @@ -66,7 +66,9 @@ my ( $self, $conf ) = @_; my $prefix = $conf->options->get('prefix') || "/usr/local"; + $prefix =~ s{/$}{}; my $ep = $conf->options->get('exec-prefix'); + $ep =~ s{/$}{} if defined $ep; my $eprefix = $ep ? $ep : $prefix; # --bindir=DIR user executables [EPREFIX/bin]