CI/msys2-mingw32: Set G_DEBUGGER environment variable

This enables us to catch access violation errors in CI and
get meaningful stacktraces with gdb.

Helps #3042

See https://docs.gtk.org/glib/running.html#environment-variables

.gitlab-ci.yml

@@ -521,6 +521,7 @@ msys2-mingw32:
     CHERE_INVOKING: "yes"
     CFLAGS: -coverage -ftest-coverage -fprofile-arcs
     PYTHONUTF8: "1"
+    G_DEBUGGER: 'gdb.exe -batch -ex "set logging enabled on" -ex "attach %p" -ex "signal-event %e" -ex "c" -ex "thread apply all bt full" -ex "k"'
   script:
     - C:\msys64\usr\bin\pacman --noconfirm -Syyuu --ask 20
     - C:\msys64\usr\bin\bash .gitlab-ci/show-execution-environment.sh
@@ -535,6 +536,7 @@ msys2-mingw32:
     expire_in: 1 week
     paths:
       - _build/meson-logs
+      - _build/gdb.txt
       - _coverage/
       - _reference/
 

.gitlab-ci/test-msys2.sh

@@ -21,7 +21,8 @@ pacman --noconfirm -S --needed \
     "${MINGW_PACKAGE_PREFIX}"-python-pip \
     "${MINGW_PACKAGE_PREFIX}"-toolchain \
     "${MINGW_PACKAGE_PREFIX}"-zlib \
-    "${MINGW_PACKAGE_PREFIX}"-libelf
+    "${MINGW_PACKAGE_PREFIX}"-libelf \
+    "${MINGW_PACKAGE_PREFIX}"-gdb
 
 mkdir -p _coverage
 mkdir -p _ccache
@@ -75,4 +76,4 @@ fi
 # can then pull it from there — see https://gitlab.gnome.org/GNOME/gtk/-/blob/docs-gtk-org/README.md
 mkdir -p _reference/
 mv _build/docs/reference/glib/glib-win32-2.0/ _reference/glib-win32/
-mv _build/docs/reference/gio/gio-win32-2.0/ _reference/gio-win32/
+mv _build/docs/reference/gio/gio-win32-2.0/ _reference/gio-win32/