bug#50924: automake-1.16: error: unrequested trace '$n'

[Karl Berry]

    automake-1.16: error: unrequested trace '$n'

Thanks for the report, but it does not happen for me on CentOS 7, using
automake-1.16.4. The changes in 1.16.x have been pretty unrelated to
autoreconf as far as I can recall, so the cygwin vs. native Unix seems a
more likely candidate to me for the culprit, but who knows.

After downloading from https://github.com/crosstool-ng/crosstool-ng,
for me running ./bootstrap ends like this:

INFO  :: *** Running autoreconf
configure.ac:96: warning: AC_PROG_LEX without either yywrap or noyywrap is 
obsolete
./lib/autoconf/programs.m4:716: _AC_PROG_LEX is expanded from...
./lib/autoconf/programs.m4:709: AC_PROG_LEX is expanded from...
configure.ac:96: the top level
configure.ac:293: warning: The macro `AC_HEADER_STDC' is obsolete.
configure.ac:293: You should run autoupdate.
./lib/autoconf/headers.m4:704: AC_HEADER_STDC is expanded from...
configure.ac:293: the top level
INFO  :: *** Done!

I don't think those two "obsolete" warnings (which are coming from
autoconf, not automake) are relevant to the problem, but again, who knows.

Maybe you or someone else on Cygwin can pursue. --best, karl.