Add prompt error stacktrace if Debug = $true

[dahlbyk]

To help troubleshoot errors like #558.

[rkeithhill]

How about we change this line to:

                Write-Verbose "PoshGitVcsPrompt error details:" -Verbose
                Write-Verbose ($_ | Format-List * -Force | Out-String) -Verbose

Then we'd get more error info (including the script stacktrace) e.g.:

[PoshGitVcsPrompt error: kaboom]~\GitHub\dahlbyk\posh-git
04-14 12:15:30 280ms 2> $GitPromptSettings.Debug = $true

VERBOSE: 00010:Getting status
VERBOSE: 00060:Parsing status
VERBOSE: 00064:Status: ## rkeithhill/change-debugprompt...origin/rkeithhill/change-debugprompt
VERBOSE: 00066:Status:  M src/GitPrompt.ps1
VERBOSE: 00067:Building status object
VERBOSE: 00087:Finished
VERBOSE: PoshGitVcsPrompt error details:
VERBOSE:

PSMessageDetails      :
Exception             : System.Management.Automation.RuntimeException: kaboom
TargetObject          : kaboom
CategoryInfo          : OperationStopped: (kaboom:String) [], RuntimeException
FullyQualifiedErrorId : kaboom
ErrorDetails          :
InvocationInfo        : System.Management.Automation.InvocationInfo
ScriptStackTrace      : at Write-GitWorkingDirStatusSummary, C:\Users\Keith\GitHub\dahlbyk\posh-git\src\GitPrompt.ps1: line 776
                        at Write-GitStatus, C:\Users\Keith\GitHub\dahlbyk\posh-git\src\GitPrompt.ps1: line 202
                        at <ScriptBlock>, C:\Users\Keith\GitHub\dahlbyk\posh-git\src\GitPrompt.ps1: line 862
                        at <ScriptBlock>, C:\Users\Keith\GitHub\dahlbyk\posh-git\src\GitPrompt.ps1: line 855
                        at Global:Write-VcsStatus, C:\Users\Keith\GitHub\dahlbyk\posh-git\src\GitPrompt.ps1: line 855
                        at <ScriptBlock>, C:\Users\Keith\GitHub\dahlbyk\posh-git\src\posh-git.psm1: line 76
                        at <ScriptBlock>, <No file>: line 1
PipelineIterationInfo : {}

But note that this will note capture any errors in the built-in prompt function as that function calls this one.

[dahlbyk]

👍 consolidated into a single Write-Verbose for no particular reason.

But note that this will not capture any errors in the built-in prompt function as that function calls this one.

True. I'm content with this for 0.x; the prompt function changes substantially in 1.0 anyway.

Though it occurs to me that this whole change isn't all that useful as folks can just look at $Error to see what went wrong in either case. 🤷‍♂️

[rkeithhill]

RE $Error - that is true although the error of interest may not always be in $Error[0] so a little spelunking may be called for.