Can no longer terragrunt apply with latest version inside a docker container

[imavroukakis]

I am running plan inside our CI container in the latest version of the module (4.2.1) and I am getting a Python runtime not found error.

╷
│ Error: External Program Execution Failed
│ 
│   with module.tunnel-open-alert.module.cloudtrail-to-slack.module.lambda.data.external.archive_prepare[0],
│   on .terraform/modules/tunnel-open-alert.cloudtrail-to-slack.lambda/package.tf line 10, in data "external" "archive_prepare":
│   10:   program = [local.python, "${path.module}/package.py", "prepare"]
│ 
│ The data source received an unexpected error while attempting to execute
│ the program.
│ 
│ Program: /usr/bin/python3
│ Error Message: Traceback (most recent call last):
│   File "/builds/alerts/envs/sandbox/.terragrunt-cache/pBKM1yebe01OCi_wMCkS_mT1Myg/3j-9NBSYy0zYCrfs0LXAX1ZEi9M/modules/.terraform/modules/tunnel-open-alert.cloudtrail-to-slack.lambda/package.py", line 1628, in <module>
│     main()
│   File "/builds/alerts/envs/sandbox/.terragrunt-cache/pBKM1yebe01OCi_wMCkS_mT1Myg/3j-9NBSYy0zYCrfs0LXAX1ZEi9M/modules/.terraform/modules/tunnel-open-alert.cloudtrail-to-slack.lambda/package.py", line 1624, in main
│     exit(args.command(args))
│          ^^^^^^^^^^^^^^^^^^
│   File "/builds/alerts/envs/sandbox/.terragrunt-cache/pBKM1yebe01OCi_wMCkS_mT1Myg/3j-9NBSYy0zYCrfs0LXAX1ZEi9M/modules/.terraform/modules/tunnel-open-alert.cloudtrail-to-slack.lambda/package.py", line 1423, in prepare_command
│     build_plan = bpm.plan(source_path, query)
│                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
│   File "/builds/alerts/envs/sandbox/.terragrunt-cache/pBKM1yebe01OCi_wMCkS_mT1Myg/3j-9NBSYy0zYCrfs0LXAX1ZEi9M/modules/.terraform/modules/tunnel-open-alert.cloudtrail-to-slack.lambda/package.py", line 801, in plan
│     pip_requirements_step(pip_requirements, prefix,
│   File "/builds/alerts/envs/sandbox/.terragrunt-cache/pBKM1yebe01OCi_wMCkS_mT1Myg/3j-9NBSYy0zYCrfs0LXAX1ZEi9M/modules/.terraform/modules/tunnel-open-alert.cloudtrail-to-slack.lambda/package.py", line 675, in pip_requirements_step
│     raise RuntimeError(
│ RuntimeError: Python interpreter version equal to defined lambda runtime
│ (python3.10) should be available in system PATH
│ 
│ State: exit status 1
╵

I am 100% certain that the container has the correct Python runtime and is accessible via PATH

953eab93b4a5:/usr/app/deployment# python --version
Python 3.11.8

953eab93b4a5:/usr/app/deployment# which python
/usr/bin/python
953eab93b4a5:/usr/app/deployment# which python3
/usr/bin/python3
953eab93b4a5:/usr/app/deployment# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Bizarrely, if I set the variable lambda_build_in_docker to true , plan passes, but naturally, apply fails