diff --git a/contrib/mobile/utils/Android.cmake b/contrib/mobile/utils/Android.cmake
index 6b9917aca3573b84f01f05fa73dd2921e2571a75..9677277209c358d5388d1d3db7182e11e934b174 100644
--- a/contrib/mobile/utils/Android.cmake
+++ b/contrib/mobile/utils/Android.cmake
@@ -813,8 +813,8 @@ if( ARMEABI OR ARMEABI_V7A )
   # It is recommended to use the -mthumb compiler flag to force the generation
   # of 16-bit Thumb-1 instructions (the default being 32-bit ARM ones).
   # O3 instead of O2/Os in release mode - like cmake sets for desktop gcc
-  set( _CMAKE_CXX_FLAGS_RELEASE "-mthumb -O3" )
-  set( _CMAKE_C_FLAGS_RELEASE   "-mthumb -O3" )
+  set( _CMAKE_CXX_FLAGS_RELEASE "-mthumb -O2 -g" )
+  set( _CMAKE_C_FLAGS_RELEASE   "-mthumb -O2 -g" )
   set( _CMAKE_CXX_FLAGS_DEBUG "-marm -Os -finline-limit=64" )
   set( _CMAKE_C_FLAGS_DEBUG   "-marm -Os -finline-limit=64" )
  else()
diff --git a/contrib/mobile/utils/onelab_android_build.sh b/contrib/mobile/utils/onelab_android_build.sh
index 7738123ef78050a95817b2326aa68f1b8c6e8a6a..48c623d270e89af8b4e6934115543fc8f7ec232e 100755
--- a/contrib/mobile/utils/onelab_android_build.sh
+++ b/contrib/mobile/utils/onelab_android_build.sh
@@ -38,7 +38,7 @@ fi
 cd $gmsh_svn/build_android
 cmake $cmake_default -DENABLE_BLAS_LAPACK=1 -DENABLE_BUILD_SHARED=1 -DENABLE_MATHEX=1 -DENABLE_MESH=1 -DENABLE_ONELAB=1 -DENABLE_PARSER=1 -DENABLE_POST=1 -DENABLE_ANN=1 -DENABLE_TETGEN=1 -DENABLE_KBIPACK=1 -DENABLE_GMP=0 -DENABLE_ZIPPER=1 -DBLAS_LIB="$petsc_lib/libf2cblas.so" -DLAPACK_LIB="$petsc_lib/libf2clapack.so" ..
 check
-make androidGmsh -j$cmake_thread
+make androidGmsh VERBOSE=1 -j$cmake_thread
 check
 make get_headers
 check
@@ -120,10 +120,13 @@ done < <($android_sdk/tools/android list target | grep -A 5 "id:")
 # cp utils/ant.properties build_android/Onelab/
 
 # to re-install on the device:
-# $android_sdk/platform-tools/adb install -r $gmsh_svn/contrib/mobile/build_android/Onelab/bin/Onelab-release.apk
+# ~/android-sdk/platform-tools/adb install -r build_android/Onelab/bin/Onelab-release.apk
 
 # to launch the app on the device:
-# $android_sdk/platform-tools/adb shell am start -n org.geuz.onelab/org.geuz.onelab.SplashScreen
+# ~/android-sdk/platform-tools/adb shell am start -n org.geuz.onelab/org.geuz.onelab.SplashScreen
 
 # to debug and check the log:
-# $android_sdk/tools/ddms
+# ~/android-sdk/tools/ddms
+
+# see stack traces after crashes:
+# ~/android-sdk/platform-tools/adb logcat | ~/android-ndk-r8b/ndk-stack -sym build_android/