When building bsd-user/freebsd/os-proc.c, you get this error if the ncurses port is installed:

/usr/ports/emulators/qemu-user-static/work/qemu-bsd-user-ec807d10/bsd-user/freebsd/os-proc.c:307:33: error:
      use of undeclared identifier 'O_CLOEXEC'
        fd = open(p, O_RDONLY | O_CLOEXEC);
                                ^
1 error generated.
gmake[3]: *** [/usr/ports/emulators/qemu-user-static/work/qemu-bsd-user-ec807d10/rules.mak:60: bsd-user/freebsd/os-proc.o] Error 1

'pkg-config --cflags ncurses' gives:
-I/usr/local/include -I/usr/local/include/ncurses -D_BSD_TYPES -D__BSD_VISIBLE -D_POSIX_C_SOURCE=200112L -D_XOPEN_SOURCE=600

Either -D_POSIX_C_SOURCE=200112L or -D_XOPEN_SOURCE=600
prevent O_CLOEXEC from being defined in fcntl.h


The [forthcoming] patch avoids adding the ncurses -D flags.  It also removes an obsolete part of post-patch that is not required given the current qemu source (which has -lelf in configure now).

I've also opened an inquiry upstream with ncurses to see if those -D flags can't just be removed from its pkg-config files.

In the mean time, a local patch for the qemu port might be useful to avoid build errors for people who have ncurses installed.

p.s. this only occurs in the most recent qemu-sbruno update - before that 'configure' didn't invoke "pkg-config --cflags ncurses".