Re: C++ libtool build error?

[Bruno Haible]

Hi Simon,

> Recently gnulib added some self-tests written in C++ for otherwise
> C-only modules.  When imported into libidn (otherwise a strictly C
> library), this leads to an error message:
> 
> /bin/bash ../libtool --preserve-dup-deps  --mode=link g++     -o 
> test-fcntl-h-c++ test-fcntl-h-c++.o libtests.a ../gl/libgnu.la libtests.a    
> libtool: link: unable to infer tagged configuration
> libtool: link: specify a tag with `--tag'
> make[4]: *** [test-fcntl-h-c++] Error 1
> make[4]: Leaving directory `/home/jas/src/libidn/gltests'

Hmm. When I do
  $ ./gnulib-tool --create-testdir --dir=/tmp/testdir --with-tests --libtool 
fcntl-h
and configure and build that testdir, everything works fine, including these
commands:

...
g++ -DHAVE_CONFIG_H -I.  -I. -I. -I.. -I./.. -I../gllib -I./../gllib    -MT 
test-fcntl-h-c++.o -MD -MP -MF .deps/test-fcntl-h-c++.Tpo -c -o 
test-fcntl-h-c++.o test-fcntl-h-c++.cc
mv -f .deps/test-fcntl-h-c++.Tpo .deps/test-fcntl-h-c++.Po
/bin/sh ./libtool   --mode=link g++     -o test-fcntl-h-c++ test-fcntl-h-c++.o 
../gllib/libgnu.la   
libtool: link: g++ -o test-fcntl-h-c++ test-fcntl-h-c++.o  
../gllib/.libs/libgnu.a
...

This is for both --disable-shared and --enable-shared, with or without
--preserve-dup-deps. So I guess you have an older version of libtool?
The version that works for me is 2.2.6.

Or maybe you have other options as part of the LT_INIT invocation in
configure.ac?

Bruno