@Marvin I am using Prefect 2.x. I used a script in my prefect.deployments.steps.run_shell_script in the push section of my prefect.yaml file. It reported that the “export” command was not found. What shell is used when running a multi-line script? How can I export an environment variable?

By default, Prefect's

run_shell_script

does not expand environment variables. You need to explicitly set

expand_env_vars: true

to allow environment variables to be expanded in your script. Here's an example configuration to export an environment variable correctly:

yaml
- prefect.deployments.steps.run_shell_script:
    id: set-env
    script: |
        export MY_VAR="my_value"
        echo $MY_VAR
    stream_output: true
    expand_env_vars: true

Adding

expand_env_vars: true

ensures that your script can properly use the

export

command and other environment variable operations. For more details, you can refer to the Prefect 2.x documentation. If you have further questions or run into issues, feel free to ask!

@Marvin that isn’t what I asked. I am getting the error “FileNotFoundError: [Errno 2] No such file or directory: ‘export’” when I run the following pull step:

- prefect.deployments.steps.run_shell_script:
      id: clone_vgt
      stream_output: true
      script: |
        export BRANCH=${BRANCH:-}

The issue you're encountering, where the

export

command is not found, typically arises because the default shell or environment in which the script is being run does not recognize the

export

command. Here's a solution to ensure that the script runs in a compatible shell (like bash):

yaml
- prefect.deployments.steps.run_shell_script:
    id: clone_vgt
    stream_output: true
    script: |
      #!/bin/bash
      export BRANCH=${BRANCH:-}
    shell: /bin/bash

In this example, I've explicitly set the shell as

/bin/bash

by adding a shebang line (

#!/bin/bash

) and specifying the

shell

parameter. This ensures that your script runs in the bash shell, which supports the

export

command. If you want to explore more about this, here's the Prefect 2.x documentation. Feel free to ask if you have any more questions!