Here are a few tricks that you can use to make maintainership easier:
ltmain.in, I keep a permanent libtool script in my
PATH, which sources ltmain.in directly.
The following steps describe how to create such a script, where
/home/src/libtool is the directory containing the libtool source
tree, /home/src/libtool/libtool is a libtool script that has been
configured for your platform, and ~/bin is a directory in your
PATH:
trick$ cd ~/bin
trick$ sed 's%^\(macro_version=\).*$%\1@VERSION@%;
s%^\(macro_revision=\).*$%\1@package_revision@%;
/^# ltmain\.sh/q' /home/src/libtool/libtool > libtool
trick$ echo '. /home/src/libtool/ltmain.in' >> libtool
trick$ chmod +x libtool
trick$ libtool --version
ltmain.sh (GNU @PACKAGE@@TIMESTAMP@) @VERSION@
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
trick$
The output of the final ‘libtool --version’ command shows that the
ltmain.in script is being used directly. Now, modify
~/bin/libtool or /home/src/libtool/ltmain.in directly in
order to test new changes without having to rerun configure.