On HP-UX, the default C compiler is not ANSI C compatible. If GNU CC is not installed, it is recommended to use the following options in order to use an ANSI C compiler:
./configure CC="cc -Ae -D_XOPEN_SOURCE=500"
and if that doesn't work, install pre-built binaries of GCC for HP-UX.
On OSF/1 a.k.a. Tru64, some versions of the default C compiler cannot
parse its <wchar.h> header file. The option -nodtk can be
used as a workaround. If GNU CC is not installed, it is therefore
recommended to try
./configure CC="cc"
and if that doesn't work, try
./configure CC="cc -nodtk"
On Solaris, don't put /usr/ucb early in your PATH. This
directory contains several dysfunctional programs; working variants
of these programs are available in /usr/bin. So, if you need
/usr/ucb in your PATH, put it after /usr/bin.
On Haiku, software installed for all users goes in /boot/common, not /usr/local. It is recommended to use the following options:
./configure --prefix=/boot/common