How do you call msdeploy from powershell when the parameters have spaces?

I'm running into a problem with spaces in my parameters that I try to send into msdeploy from a powershell script.

There are a number of other related articles but none of them solve the problem.
Problems Using Power Shell And MSDeploy.
Similar SO issue that doesn't work: How to run exe in powershell with parameters with spaces and quotes
PowerShell BUG: Executing commands which require quotes and variables is practically impossible
Another SO issue that doesn't work:Passing parameters in PowerShell 2.0

The simplest example that succeeds and then fails when I make it more complicated is just dumping the default web site.

$msdeploy = "C:\Program Files\IIS\Microsoft Web Deploy\msdeploy.exe"
&$msdeploy -verb:dump -source:appHostConfig=`'default web site`' -verbose
==SUCCESS

This one?

$sitename="default web site"
&$msdeploy -verb:dump -source:appHostConfig=$sitename -verbose
==FAIL with the following error
msdeploy.exe : Error: Unrecognized argument '"-source:"appHostConfig=default'. All arguments must begin with "-".
At C:\xxx\test.ps1:122 char:6
+ &
+ CategoryInfo : NotSpecified: (Error: Unrecogn...begin with "-".:String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError
Error count: 1.

The following variations have also failed
#FAIL
$sitename=`'default web site`'
$sitename=`'"default web site"`'
$sitename="`'default web site`'"
$sitename="default web site"
$sitename="'default web site'"

&$msdeploy -verb:dump "-source:appHostConfig=$sitename" -verbose
&$msdeploy -verb:dump -source:appHostConfig="$sitename" -verbose
&$msdeploy -verb:dump -source:appHostConfig='$sitename' -verbose
&$msdeploy -verb:dump -source:appHostConfig=`'$sitename`' -verbose
&$msdeploy -verb:dump -source:appHostConfig=`"$sitename`" -verbose

I'm at a loss. Everyone I work with is at a loss. Seriously this sucks. I loved Powershell. I loved msdeploy. I can't say that I love putting them together. It looks like it may have been easier to focus on the API instead of the cli.

EDIT:

The parameters in the string array suggested by Emperor XLII works well. An alternative solution is presented in the following article: The trials and tribulations of using MSDeploy with PowerShell

function PushToTarget([string]$server, [string]$remotePath, [string]$localPath) {
    cmd.exe /C $("msdeploy.exe -verb:sync -source:contentPath=`"{0}`" -dest:computerName=`"{1}`",contentPath=`"{2}`" -whatif" -f $localPath, $server, $remotePath )
}

Solution

Using the technique from Keith's answer to How to run exe in powershell with parameters with spaces and quotes question you linked to, running echoargs -verb:dump -source:appHostConfig=$sitename -verbose gave me this output:

Arg 0 is <-verb:dump>
Arg 1 is <-source:appHostConfig=default>
Arg 2 is <web>
Arg 3 is <site>
Arg 4 is <-verbose>

This would explain the invalid argument of appHostConfig=default that msdeploy was seeing.

Running echoargs -verb:dump "-source:appHostConfig=$sitename" -verbose, with $sitename = "default web site", appears to result in the desired arguments:

Arg 0 is <-verb:dump>
Arg 1 is <-source:appHostConfig=default web site>
Arg 2 is <-verbose>

Though from your list, it appears that this did not work for you.

Another method you might try is building up the list of arguments in an array, which powershell can automatically escape. For example, this gives the same output as above:

[string[]]$msdeployArgs = @(
  "-verb:dump",
  "-source:appHostConfig=$sitename",
  "-verbose"
)
echoargs $msdeployArgs