snap: enable building using current remote-build

As sources are re-packed, references are broken.

Signed-off-by: Sergio Schvezov <sergio.schvezov@canonical.com>

tools/snapcraft-override-build.sh → snap/local/scripts/snapcraft-override-build.sh

@@ -9,7 +9,7 @@ PYTHON_PACKAGE_PATH="${SNAPCRAFT_PART_INSTALL}/usr/lib/python3.8/"
 
 # Apply patches
 echo "Patching ctypes..."
-patch -s -b "${PYTHON_PACKAGE_PATH}/ctypes/__init__.py" "${SNAPCRAFT_PROJECT_DIR}/patches/ctypes_init.diff"
+patch -s -b "${PYTHON_PACKAGE_PATH}/ctypes/__init__.py" "${SNAPCRAFT_PROJECT_DIR}/snap/local/patches/python/ctypes_init.diff"
 
 # Save patches to allow rebuilding
 mkdir -p patched/ctypes

snap/snapcraft.yaml

@@ -117,7 +117,7 @@ parts:
       # Remove so the link can be recreated on re-builds
       rm -f "$TRIPLET_PATH/libsodium.so"
       ln -s "$LIBSODIUM" "$TRIPLET_PATH/libsodium.so"
-      $SNAPCRAFT_PROJECT_DIR/tools/snapcraft-override-build.sh
+      $SNAPCRAFT_PROJECT_DIR/snap/local/scripts/snapcraft-override-build.sh
 
   snapcraft:
     source: .
@@ -128,6 +128,8 @@ parts:
         - setuptools<66  # Limited to < 66 because we need `pkg_resources` and because `python-apt` doesn't build with the latest.
     requirements:
         - requirements.txt
+    constraints:
+        - constraints.txt
     organize:
         # Put snapcraftctl into its own directory that can be included in the PATH
         # without including other binaries.