[gimp/wip/Jehan/incremental-win-installer-improvements] build: more optional feature to Windows installer.

[Jehan <jehanp src gnome org>]

commit 52fc208a4aac6665c7536a9ff73241d24a494dd5
Author: Jehan <jehan girinstud io>
Date:   Fri May 14 20:27:33 2021 +0200

    build: more optional feature to Windows installer.
    
    headers-git package needed for DirectInput.

 build/windows/gitlab-ci/build-gimp-msys2.sh | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
---
diff --git a/build/windows/gitlab-ci/build-gimp-msys2.sh b/build/windows/gitlab-ci/build-gimp-msys2.sh
index 42ae685b08..898e590308 100644
--- a/build/windows/gitlab-ci/build-gimp-msys2.sh
+++ b/build/windows/gitlab-ci/build-gimp-msys2.sh
@@ -5,17 +5,18 @@ set -e
 if [[ "$MSYSTEM" == "MINGW32" ]]; then
     export ARTIFACTS_SUFFIX="-w32"
     export MSYS2_ARCH="i686"
-    export ACLOCAL_FLAGS="-I/c/msys64/mingw32/share/aclocal"
-    export PATH="/c/msys64/mingw32/bin:$PATH"
+    export MSYS2_PREFIX="/c/msys64/mingw32"
     export GIMP_OPTIONS="--with-vala=no --enable-vala=no"
 else
     export ARTIFACTS_SUFFIX="-w64"
     export MSYS2_ARCH="x86_64"
-    export ACLOCAL_FLAGS="-I/c/msys64/mingw64/share/aclocal"
-    export PATH="/c/msys64/mingw64/bin:$PATH"
+    export MSYS2_PREFIX="/c/msys64/mingw64/"
     export GIMP_OPTIONS=""
 fi
 
+export ACLOCAL_FLAGS="-I${MSYS2_PREFIX}/share/aclocal"
+export PATH="${MSYS2_PREFIX}/bin:$PATH"
+
 # Why do we even have to remove these manually? The whole thing is
 # messed up, but it looks like the Gitlab runner fails to clean properly
 # (it spews a bunch of "failed to remove" warnings at runner start, then
@@ -53,6 +54,7 @@ pacman --noconfirm -S --needed \
     mingw-w64-$MSYS2_ARCH-graphviz \
     mingw-w64-$MSYS2_ARCH-gtk3 \
     mingw-w64-$MSYS2_ARCH-gtk-doc \
+    mingw-w64-$MSYS2_ARCH-headers-git \
     mingw-w64-$MSYS2_ARCH-iso-codes \
     mingw-w64-$MSYS2_ARCH-json-c \
     mingw-w64-$MSYS2_ARCH-json-glib \
@@ -100,7 +102,9 @@ ccache --show-stats
 
 mkdir "_build${ARTIFACTS_SUFFIX}"
 cd "_build${ARTIFACTS_SUFFIX}"
-../autogen.sh --prefix="${GIMP_PREFIX}" --enable-windows-installer ${GIMP_OPTIONS}
+../autogen.sh --prefix="${GIMP_PREFIX}" --enable-windows-installer \
+              --with-directx-sdk="${MSYS2_PREFIX}" \
+              ${GIMP_OPTIONS}
 make -j4
 make install
 cd ..