Problem in building Emacs 25.1 on Ubuntu 16.04.1

[Hantang Liu]

Hi everyone. I came across a problem when building emacs-25.1 on Ubuntu 16.04.1. After successfully running

./autogen.sh
./configure --with-xwidgets --with-cairo --prefix=$HOME

I run `make` then the following error shows up

In file included from binary-io.c:3:0:
binary-io.h: In function ‘set_binary_mode’:
binary-io.h:57:10: error: ‘O_BINARY’ undeclared (first use in this function)
return O_BINARY;

I googled around and could not solve it by myself, do you have any ideas? Thanks.

--
Hantang Liu

[Eli Zaretskii]

> Date: Sun, 18 Sep 2016 23:33:43 +0800 (GMT+08:00)
> From: "Hantang Liu" <liuha...@zju.edu.cn>

>
> In file included from binary-io.c:3:0:
> binary-io.h: In function ‘set_binary_mode’:
> binary-io.h:57:10: error: ‘O_BINARY’ undeclared (first use in this function)
> return O_BINARY;

O_BINARY is supposed to be defined in lib/fcntl.h, please look there
for why this doesn't work for you.

In any case, I suggest to report this using report-emacs-bug.

[Liu Hantang]

I delved into `lib/fcntl.h` and found `O_BINARY` is defined in it.
Then I found that `binary-io.h` includes `fcntl.h` with `#include <fcntl.h>`,
which means it mightuse my system's version of `fcntl.h`. I found that system's
`fcntl.h` has no `O_BINARY` defined and I happened to have `export C_INCLUDE_PATH=/usr/include...`
in my .zshrc so the compiler used system's instead of emacs'(which is supposed to be used).
I deleted the `C_INCLUDE_PATH` definition in `.zshrc` then successfully compiled it.

Thanks for the help!

============================

> > Date: Sun, 18 Sep 2016 23:33:43 +0800 (GMT+08:00)

> > From: "Hantang Liu" <address@hidden>

> >
> > In file included from binary-io.c:3:0:
> > binary-io.h: In function ‘set_binary_mode’:
> > binary-io.h:57:10: error: ‘O_BINARY’ undeclared (first use in this
> > function)
> > return O_BINARY;
>
> O_BINARY is supposed to be defined in lib/fcntl.h, please look there
> for why this doesn't work for you.
>
> In any case, I suggest to report this using report-emacs-bug.

--
Hantang Liu