Detected characters in arguments that may not be executed correctly by the shell. Please escape special characters using backtick (`)

Question

When running the below azure pipeline, I get the error:

Detected characters in arguments that may not be executed correctly by the shell. Please escape special characters using backtick (`).

This happens because of the Unicode character £ inside the password. For simplification, I put the password inside the script variable, but the real pipeline get it from it's parameters.

It seams to be an error at the azure task PowerShell@2 when generating the temporary script.

How to allow this special characters to be passed?

The pipeline script:

variables:
- name: password
  value: £f1l1

pool:
  vmImage: windows-latest
  
steps:                          
- task: PowerShell@2
  inputs:
    filePath: 'someScript.ps1'
    arguments: "-password $(password)"

Answer 1

Using environment variables set at the task level is probably the best way to avoid escaping/encoding issues. Also, it is the recommended approach when dealing with sensitive information such as passwords.

Using a Powershell script with parameters

Test script:

# scripts/someScript1.ps1

param (
   [string]$password
)

Write-Host "Password: $password"

Test pipeline:

variables:
  - name: password
    value: £f1l1

steps:
  - checkout: self

  - task: PowerShell@2
    displayName: 'Run script'
    inputs:
      targetType: 'inline'
      script: |
        ./someScript1.ps1 -password $Env:MyPassword
      workingDirectory: '$(Build.SourcesDirectory)/scripts'
    env:
      MyPassword: $(password) # <-------------------- environment variable set here

Running the pipeline:

Using a Powershell script with environment variables

Test script:

# scripts/someScript2.ps1

Write-Host "Password: ${Env:MyPassword}"

Test pipeline:

variables:
  - name: password
    value: £f1l1

steps:
  - checkout: self

  - task: PowerShell@2
    displayName: 'Run script with environment variable'
    inputs:
      filePath: '$(Build.SourcesDirectory)/scripts/someScript2.ps1'
    env:
      MyPassword: $(password) # <-------------------- environment variable set here

Running the pipeline: