diff --git a/meson.build b/meson.build
index e1b74508057fcbbf0361d40ec57495d610886fb0..6c155a9bf4fdbbd7bf35ebee6d53b78699a9ba4b 100644
--- a/meson.build
+++ b/meson.build
@@ -1951,7 +1951,8 @@ subdir('app-tools')
 # tool.
 
 gimp_run_env=environment()
-gimp_run_env.set('GIMP_GLOBAL_BUILD_ROOT', meson.global_build_root())
+gimp_run_env.set('GIMP_GLOBAL_BUILD_ROOT',  meson.global_build_root())
+gimp_run_env.set('GIMP_GLOBAL_SOURCE_ROOT', meson.global_source_root())
 
 if meson.can_run_host_binaries() and have_gobject_introspection
   if enable_console_bin
diff --git a/tools/debug-in-build-gimp.py b/tools/debug-in-build-gimp.py
new file mode 100644
index 0000000000000000000000000000000000000000..7225a7c4e4e10ae0bb853a7c1ba6611f01aa4bb5
--- /dev/null
+++ b/tools/debug-in-build-gimp.py
@@ -0,0 +1,8 @@
+def my_signal_handler (event):
+  if (isinstance(event, gdb.SignalEvent)):
+    gdb.write("Eeeeeeeeeeeek: in-build GIMP crashed!\n")
+    gdb.execute('info threads')
+    gdb.execute("thread apply all backtrace full")
+
+gdb.events.stop.connect(my_signal_handler)
+gdb.execute("run")
diff --git a/tools/in-build-gimp.sh b/tools/in-build-gimp.sh
index b1254e7e980148a24d6e61db62bc998d7b4d9dbe..913fd19c80f05aa0c640b2ffcfde25b014043c20 100755
--- a/tools/in-build-gimp.sh
+++ b/tools/in-build-gimp.sh
@@ -24,7 +24,13 @@ if [ -n "$GIMP_TEMP_UPDATE_RPATH" ]; then
   unset IFS
 fi
 
-cat /dev/stdin | $GIMP_SELF_IN_BUILD "$@"
+if command -v gdb; then
+  echo RUNNING: cat /dev/stdin "|" gdb --batch -x "$GIMP_GLOBAL_SOURCE_ROOT/tools/debug-in-build-gimp.py" --args $GIMP_SELF_IN_BUILD "$@"
+  cat /dev/stdin | gdb --return-child-result --batch -x "$GIMP_GLOBAL_SOURCE_ROOT/tools/debug-in-build-gimp.py" --args $GIMP_SELF_IN_BUILD "$@"
+else
+  echo RUNNING: cat /dev/stdin "|" $GIMP_SELF_IN_BUILD "$@"
+  cat /dev/stdin | $GIMP_SELF_IN_BUILD "$@"
+fi
 
 if [ -n "$GIMP_TEMP_UPDATE_RPATH" ]; then
   export IFS=":"