Hi Paul, > Can you reproduce the problem this way? > > ./gnulib-tool --dir foo --create-testdir unistd > cd foo > ./configure > make > make check
No, that sequence of commands gives no error. The check phase reports 12 out of 12 successful tests. The relevant bit from config.log is available at <http://pastebin.com/Y9qgVH2a>. > As I understand it, GCC 5.3.1 should not need a substitute stddef.h. > So if your system is creating one, you need to figure out why > ./configure decided that stddef.h wasn't working. Hmm. I'm observing that issue on two different Linux/x86_64 systems: both openSUSE Tumbleweed and NixOS show the same error. > Look in config.log; it should say something like this: > > configure:7608: checking for max_align_t > [ a lot of chatter ] > configure:7608: result: yes The relevant bit is at <http://pastebin.com/x7W2SyKW>. Apparently, the second (failing) build decides that max_align_t is not available, but the gnulib-generate test build thinks it is. Not sure how to explain that. For what it's worth, the full source code of my project is available at http://git.savannah.gnu.org/cgit/mini-httpd.git. Best regards, Peter