Dealing with a failed configure when building a php extension

If you happen to get stuck when compiling a php pecl extension with a libtool error like this:

libtool: line 467: CDPATH: command not found
libtool: line 1145: func_opt_split: command not found
libtool: Version mismatch error.  This is libtool 2.2.6b, but the
libtool: definition of this LT_INIT comes from an older release.
libtool: You should recreate aclocal.m4 with macros from libtool 2.2.6b
libtool: and run autoconf again.

Try issuing the following commands:

libtoolize --force

Finally, try again to run configure and make.