如何在vsts发布任务中使用秘密变量?

我在vsts中有一个发布定义,需要访问一个密码,我在变量组中定义了一个秘密变量。我已将该组链接到此版本定义,但当我运行任务时,参数最终为空。为了得到一个秘密变量的值,我需要做什么特殊的事情吗?

使用密码的powershell任务的定义

错误输出:

2017-08-09T14:01:17.9262375Z ##[command].            'C:\agent_work\r1\a\$(AGENT.BUILDDIRECTORY)\RCV\deploys\common\Get-FromArtifactory.ps1' -repoUsername developer -repoPassword  -repoPath libs-snapshot-local
2017-08-09T14:01:18.8168538Z ##[error]C:\agent_work\r1\a\$(AGENT.BUILDDIRECTORY)\RCV\deploys\common\Get-FromArtifactory.ps1 : Missing an argument for parameter 'repoPassword'. Specify a parameter of type 'System.String' and try again.

这是我Get-FromArtifictory.ps1的开始

[CmdletBinding()]
param (
    [Parameter(Mandatory)]
    [String]
    $repoUsername,

    [Parameter()]
    [String]
    $repoPassword,

    # Other params
)
#setup credentials object for arty access
$secPassword = $repoPassword | ConvertTo-SecureString -asPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential($repoUsername, $secPassword)

修改脚本以打印部分密码:

[CmdletBinding()]
param (
    [Parameter(Mandatory)]
    [String]
    $repoUsername,

    [Parameter()]
    [String]
    $repoPassword,

#other params
)
write-host "pword $repoPassword"
write-host "1st char: $($repoPassword[0])"

2017-08-15T09:23:00.8606081Z ##[command]. 'C:\agent_work\r1\a\RCV\deploys\common\Get-FromArtifactory.ps1' -repoUsername developer -repoPassword "" -repoPath libs-snapshot-local -artifactName ipo-deposit-accounts_2.11 -artifactPath uk/gov/ipo -artifactVersion 0.1-SNAPSHOT -downloadDir C:\agent_work\r1\a
2017-08-15T09:23:02.3606174Z pword     
2017-08-15T09:23:02.3606174Z 1st char: 

与单引号相同

2017-08-15T09:22:10.6573655Z ##[command]. 'C:\agent_work\r1\a\RCV\deploys\common\Get-FromArtifactory.ps1' -repoUsername developer -repoPassword '' -repoPath libs-snapshot-local -artifactName ipo-deposit-accounts_2.11 -artifactPath uk/gov/ipo -artifactVersion 0.1-SNAPSHOT -downloadDir C:\agent_work\r1\a
2017-08-15T09:22:11.2198723Z pword 
2017-08-15T09:22:11.3761178Z 1st char: