$NetBSD$

Use pkgsrc libtool.

--- library/backtrace/crates/backtrace-sys/src/libbacktrace/configure.orig	2020-10-07 08:04:03.000000000 +0000
+++ library/backtrace/crates/backtrace-sys/src/libbacktrace/configure
@@ -7916,7 +7916,7 @@ fi
 LIBTOOL_DEPS="$ltmain"
 
 # Always use our own libtool.
-LIBTOOL='$(SHELL) $(top_builddir)/libtool'
+LIBTOOL='libtool'
 
 
 
