Building Emacs on MSYS2 (was: Build failure for Emacs master)

["Óscar Fuentes" <ofv@wanadoo.es>]

Eli Zaretskii <eliz@gnu.org> writes:

>> In MSYS2 and other OS there are *-git packages just to have the last 
>> development source not because that people aims to develop and maintain 
>> the applications of those packages..
>
> I'd urge all those who are tracking development sources to please use
> the official established build procedure.  Using 3rd-party packages
> whose procedures deviate from the project instructions is susceptible
> to bumping into problems that stem from using those deviant
> procedures, which is an added maintenance burden I think we'd like to
> avoid.  Also, doing so means less testing for the official build
> procedures.

Currently this is the code for configuring the build of emacs-git on
MSYS2 MinGW-packages:

build() {
  [[ -d "${srcdir}/build-${MINGW_CHOST}" ]] && rm -rf "${srcdir}/build-${MINGW_CHOST}"
  mkdir -p "${srcdir}/build-${MINGW_CHOST}"
  cd "build-${MINGW_CHOST}"

  local with_wide_int='no'

  if test "${CARCH}" == 'x86_64'; then
    with_wide_int='yes'
  fi

  CPPFLAGS="-DNDEBUG -isystem ${MINGW_PREFIX}/include"
  CFLAGS="-pipe -O3 -fomit-frame-pointer -funroll-loops"
  LDFLAGS="-s -Wl,-s"
  "${srcdir}/${_realname}/configure" \
    --prefix="${MINGW_PREFIX}" \
    --build="${MINGW_CHOST}" \
    --with-wide-int="${with_wide_int}" \
    --with-sound="yes" \
    --with-file-notification="yes" \
    --without-gpm \
    --without-gconf \
    --without-gsettings \
    --without-selinux

  make
}

Apart from setting with_wide_int and adding some (unnecessary, IMHO)
optimization options, it looks like a fairly standard configuration.

The package contains two patches too. This one that looks like trying to
avoid a link problem:


--- src/image.c.orig	2014-10-15 14:18:29.088716000 +0200
+++ src/image.c	2014-10-15 15:54:12.407522800 +0200
@@ -7862,7 +7862,7 @@
   };
 
 #if defined HAVE_NTGUI && defined WINDOWSNT
-static bool init_imagemagick_functions (void);
+#define init_imagemagick_functions NULL
 #else
 #define init_imagemagick_functions NULL
 #endif



and this one that seems related to locating the source directory:

--- src/lread.c.orig	2014-11-04 20:29:22.129549000 +0100
+++ src/lread.c	2014-11-04 22:33:07.346414100 +0100
@@ -4351,6 +4351,12 @@
             } /* Vinstallation_directory != Vsource_directory */
 
         } /* if Vinstallation_directory */
+      else
+        {
+          Vsource_directory
+            = Fexpand_file_name (build_string ("../"),
+                                 Fcar (decode_env_path (0, PATH_DATA, 0)));
+        }
     }
   else                          /* !initialized */
     {


> If you can convince the MSYS2 maintainers to adopt the official build
> procedure, it would be even better.

I can change the emacs-git package for not adding those optimization
options and not setting with-wide-int. Do you think that's enough?

> Failing that, please consider
> switching back to what the project recommends, what is documented in
> the relevant INSTALL documents.

Because MSYS2 does not distribute binaries for emacs-git, I guess that
the number of people who currently uses the PKGBUILD shown above is very
small. AFAIK Angelo and others that build Emacs on MSYS2 are not using
the PKGBUILD, but following the recipe on the Emacs' docs (possibly with
their own personal modifications.)