bug in AC_PROG_CXX

[Thorsten Schütt]

Hi,

I believe that there is a bug in the AC_PROG_CXX macro. Please find attached 
the reproducer including output and config.log.

I created a virtual machine with Fedora 24 with *no* C++ compiler, built the 
master of the autoconf git repository, and created a configure file from the 
configure.ac file (calling the new autooconf):

AC_INIT(repro, 0.1, address@hidden)

AC_PROG_CXX

echo $CXX

According to the documentation: "If none of those checks succeed, then as a 
last resort set CXX to g++.” However, the configure file fails and stops before 
reaching the echo command.

checking for g++... no
checking for c++... no
checking for gpp... no
checking for aCC... no
checking for CC... no
checking for cxx... no
checking for cc++... no
checking for cl.exe... no
checking for FCC... no
checking for KCC... no
checking for RCC... no
checking for xlC_r... no
checking for xlC... no
checking for clang++... no
checking whether the C++ compiler works... no
configure: error: in `/home/schuett/repro':
configure: error: C++ compiler cannot create executables
See `config.log' for more details

I am happy to provide more information if necessary.

Regards,
  Thorsten

repro.tgz
Description: Binary data