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, schu...@zib.de) 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
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