[gimp/wip/Jehan/investigate-win-CI-bug] build: fix cross-compiled meson builds.

[Jehan <jehanp src gnome org>]

commit 25ecef0dc39dc28e2312f2d0a606837b8f2f0c03
Author: Jehan <jehan girinstud io>
Date:   Sun May 10 12:05:13 2020 +0200

    build: fix cross-compiled meson builds.
    
    A bug came with meson 0.54.1 (looking at reports, I understand it to be
    a mix of a meson bug and a patch by Debian making it a different bug).
    See:
    - https://github.com/mesonbuild/meson/issues/6115#issuecomment-593312709
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=959708
    
    In any case, our Windows cross-builds end up with (with no libdir set on
    our own): libdir=${prefix}/lib/x86_64-linux-gnu
    This is obviously wrong as confirmed by meson report comments.

 build/windows/crossbuild-gitlab-ci/build-deps.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/build/windows/crossbuild-gitlab-ci/build-deps.sh 
b/build/windows/crossbuild-gitlab-ci/build-deps.sh
index 865d051c48..e553d43e6a 100644
--- a/build/windows/crossbuild-gitlab-ci/build-deps.sh
+++ b/build/windows/crossbuild-gitlab-ci/build-deps.sh
@@ -5,7 +5,7 @@ mkdir _deps && cd _deps
 
 crossroad install lcms2 && \
 git clone --depth 1 https://gitlab.gnome.org/GNOME/babl.git && cd babl && \
-crossroad meson _build/ -Denable-gir=false && \
+crossroad meson _build/ -Denable-gir=false -Dlibdir=lib && \
 ninja -C _build install || exit 1
 cd ..
 
@@ -13,7 +13,7 @@ cd ..
 
 crossroad install json-glib && \
 git clone --depth 1 https://gitlab.gnome.org/GNOME/gegl.git && cd gegl && \
-crossroad meson _build/ -Dintrospection=false -Dsdl2=disabled && \
+crossroad meson _build/ -Dintrospection=false -Dsdl2=disabled -Dlibdir=lib && \
 ninja -C _build install || exit 1
 cd ..