Using pydantic-core py package in app and unable to cross compile to aarch64

I was working with a basic fastapi server. Build successfully for the amd64 architecture. When cross compiling for arm64 the app is not starting. When i checked the snap logs I got following:

larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 fastapidemo.run[1679]:   File "/snap/fastapidemo/x1/li                                                                                                                                                             b/python3.8/site-packages/pydantic_core/__init__.py", line 6, in <module>
-bash: syntax error near unexpected token `newline'
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 fastapidemo.run[1679]:     from ._pydantic_core import                                                                                                                                                              (
-bash: syntax error near unexpected token `('
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 fastapidemo.run[1679]: ModuleNotFoundError: No module                                                                                                                                                              named 'pydantic_core._pydantic_core'
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: snap.fastapidemo.run.service: Main process                                                                                                                                                              exited, code=exited, status=1/FAILURE
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: snap.fastapidemo.run.service: Failed with                                                                                                                                                              result 'exit-code'.
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: snap.fastapidemo.run.service: Scheduled re                                                                                                                                                             start job, restart counter is at 6.
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: Stopped Service for snap application fasta                                                                                                                                                             pidemo.run.
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: snap.fastapidemo.run.service: Start reques                                                                                                                                                             t repeated too quickly.
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: snap.fastapidemo.run.service: Failed with                                                                                                                                                              result 'exit-code'.
-bash: 2022-11-07T12:22:12+01:00: command not found
larsroot@CtrlX-X3:~$ 2022-11-07T12:22:12+01:00 systemd[1]: Failed to start Service for snap application        

It seems to be the problem with the package pydantic-core.

yaml file is as follows

name: fastapidemo
version: 0.1.2.0
summary: fastapidemo
description: 'simple demo-test1'

base: core20
confinement: strict
grade: stable

# Limit architectures as ppcel64 doesn't build currently
architectures:
  - build-on: amd64
  - build-on: arm64


apps:
  run:
    command: bin/launcher.wrapper
    daemon: simple
    plugs:
      - network-bind
      - network-status
      - network-observe
      - serial-port
      - datalayer
    environment:
       "LD_LIBRARY_PATH": "$LD_LIBRARY_PATH:$SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/lapack:$SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/blas:$SNAP/usr/lib/python3/dist-packages"
      

    
  desktop-launch:
    command: bin/desktop-launch
    plugs:
      - desktop  

parts:


  requests:
    plugin: python
    build-environment:
      - PYTHONPATH: "$SNAPCRAFT_PART_INSTALL/usr/lib/python3/dist-packages"

    stage-packages:
      - wget
      - git
      - zip 
      - libssl-dev
      - libcurl4-openssl-dev
      - libcurl-dev
      - pkg-config
      - build-essential
      - unzip
      - python3-wheel
      
    python-packages:
      - wheel
      - requests
      - flask
      - fastapi
      - uvicorn
      
      
      
 
    build-packages:
      - python3-dev
      - python3-wheel
      - build-essential
      - python3-setuptools




  datalayerdeb:
      plugin: dump
      source: https://github.com/boschrexroth/ctrlx-automation-sdk/releases/download/1.18.0/ctrlx-datalayer-1.9.1.deb
      source-type: deb
      stage-packages:
        - libzmq5
     
 
 
  shscripts:  
    source: ./shscripts/
    plugin: dump
    organize:
      '*': bin/
      

  configs:
    source: ./configs
    plugin: dump
    organize:
      'package-assets/*': package-assets/${SNAPCRAFT_PROJECT_NAME}/
      'secure-assets/*': secure-assets/${SNAPCRAFT_PROJECT_NAME}/



plugs:
  datalayer:
    interface: content
    content: datalayer
    target: $SNAP_DATA/.datalayer 


slots:
  secure-assets:
    interface: content
    content: secure-assets
    source:
      read:
        - $SNAP/secure-assets/${SNAPCRAFT_PROJECT_NAME}

  service-token:
    interface: content
    content: service-token
    source:
      write:
        - $SNAP_DATA/service-token/${SNAPCRAFT_PROJECT_NAME}

  package-assets:
    interface: content
    content: package-assets
    source:
      read:
        - $SNAP/package-assets/${SNAPCRAFT_PROJECT_NAME}