Hello, I'm trying to configure/build ngircd on AIX 6.1, and got the following error. Reporting it because it asked me nicely. root@r59s2h4:/twiki/ngircd/ngircd-20.2 # ./configure checking build system type... powerpc-ibm-aix6.1.0.0 checking host system type... powerpc-ibm-aix6.1.0.0 checking for a BSD-compatible install... ./install-sh -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... ./install-sh -c -d checking for gawk... no checking for mawk... no checking for nawk... nawk checking whether make sets $(MAKE)... yes checking for gcc... gcc checking whether the C compiler works... yes checking for C compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking for style of include used by make... GNU checking dependency style of gcc... gcc3 checking for gcc option to accept ISO C99... -std=gnu99 checking for gcc -std=gnu99 option to accept ISO Standard C... (cached) -std=gnu99 checking for gawk... (cached) nawk checking whether ln -s works... yes checking whether make sets $(MAKE)... (cached) yes checking for ranlib... ranlib checking for an ANSI C-conforming const... yes checking for inline... inline checking for function prototypes... yes checking how to run the C preprocessor... gcc -std=gnu99 -E checking for grep that handles long lines and -e... /opt/freeware/bin/grep checking for egrep... /opt/freeware/bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... no checking for string.h... (cached) yes checking whether gcc -std=gnu99 accepts -fstack-protector... no checking for ANSI C header files... (cached) yes checking for sys/wait.h that is POSIX.1 compatible... yes checking whether time.h and sys/time.h may both be included... yes checking fcntl.h usability... no checking fcntl.h presence... yes configure: WARNING: fcntl.h: present but cannot be compiled configure: WARNING: fcntl.h: check for missing prerequisite headers? configure: WARNING: fcntl.h: see the Autoconf documentation configure: WARNING: fcntl.h: section "Present But Cannot Be Compiled" configure: WARNING: fcntl.h: proceeding with the compiler's result configure: WARNING: ## ----------------------------------------- ## configure: WARNING: ## Report this to ngircd-ml@ngircd.barton.de ## configure: WARNING: ## ----------------------------------------- ## checking for fcntl.h... no configure: error: required C header missing! Merci, Aaron