Debugging a script that invokes exiftool.exe hangs

System Details

System Details Output

### VSCode version: 1.53.2 622cb03f7e070a9670c94bae1a45d78d7181fbd4 x64

### VSCode extensions:
af4jm.vscode-m3u@1.0.0
akamud.vscode-javascript-snippet-pack@0.1.6
alefragnani.Bookmarks@13.0.3
Angular.ng-template@11.2.4
anseki.vscode-color@0.4.5
anweber.vscode-tidyhtml@1.10.0
austin.code-gnu-global@0.2.2
chenxsan.vscode-standardjs@1.4.0
christian-kohler.npm-intellisense@1.3.1
christian-kohler.path-intellisense@2.3.0
CoenraadS.bracket-pair-colorizer@1.0.61
Damien.autoit@1.0.5
DavidAnson.vscode-markdownlint@0.39.0
DotJoshJohnson.xml@2.5.1
DougFinke.vscode-PSStackoverflow@0.0.2
ecmel.vscode-html-css@1.10.2
eg2.vscode-npm-script@0.3.16
esbenp.prettier-vscode@5.9.2
formulahendry.platformio@0.3.0
GrapeCity.gc-excelviewer@3.0.41
Gruntfuggly.todo-tree@0.0.199
hdg.live-html-previewer@0.3.0
HookyQR.beautify@1.5.0
humao.rest-client@0.24.4
infinity1207.angular2-switcher@0.3.3
ionutvmi.reg@1.0.2
jasonnutter.github-pr@1.0.0
leighlondon.eml@0.4.0
mechatroner.rainbow-csv@1.8.1
Mikael.Angular-BeastCode@10.0.3
ms-azure-devops.azure-pipelines@1.183.0
ms-dotnettools.csharp@1.23.9
ms-mssql.mssql@1.10.1
ms-python.python@2021.2.582707922
ms-toolsai.jupyter@2021.2.603412351
ms-vscode-remote.remote-wsl@0.53.4
ms-vscode.azure-account@0.9.6
ms-vscode.cpptools@1.2.2
ms-vscode.powershell@2021.2.2
ms-vscode.vscode-typescript-tslint-plugin@1.3.3
msjsdiag.debugger-for-chrome@4.12.12
natewallace.angular2-inline@0.0.17
nobuhito.printcode@3.0.0
nrwl.angular-console@17.0.0
oderwat.indent-rainbow@7.5.0
platformio.platformio-ide@2.3.0
quicktype.quicktype@12.0.46
RandomFractalsInc.geo-data-viewer@2.3.0
redhat.java@0.75.0
tht13.html-preview-vscode@0.2.5
twxs.cmake@0.0.17
Tyriar.lorem-ipsum@1.2.0
VisualStudioExptTeam.vscodeintellicode@1.2.11
vitaliymaz.vscode-svg-previewer@0.7.0
vscjava.vscode-java-debug@0.31.0
vscjava.vscode-java-dependency@0.18.1
vscjava.vscode-java-pack@0.12.1
vscjava.vscode-java-test@0.28.0
vscjava.vscode-maven@0.27.1
yzane.markdown-pdf@1.4.4
yzhang.markdown-all-in-one@3.4.0
Zignd.html-css-class-completion@1.20.0
zovorap.ab-html-formatter@0.0.2


### PSES version: 2.3.0.0

### PowerShell version:

Name                           Value
----                           -----
PSVersion                      7.1.2
PSEdition                      Core
GitCommitId                    7.1.2
OS                             Microsoft Windows 10.0.19042
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Issue Description

When I run the following script under the PowerShell debugger within VScode, it hangs when launching exiftool.exe:

$exiftool = (Get-Command exiftool).Path
Write-Host ("'exiftool' is '{0}' (version {1}) {{MD5={2}}}" -f $exiftool, (Get-Item $exiftool).VersionInfo.ProductVersion, (Get-Filehash -Algorithm MD5 $exiftool).Hash)
$cmd = "{0} -DateTimeOriginal {1}" -f $exiftool, (Join-Path -Path $PSScriptRoot -ChildPath 'foobar.cr2')
Write-Host ("Invoking '{0}'" -f $cmd)
Invoke-Expression $cmd

Expected Behaviour

When running outside of the debugger (in a standalone PowerShell session, or in the VScode terminal), I get the expected results:

'exiftool' is 'c:\usr\wbin\exiftool.exe' (version 12.2.1.0) {MD5=4ECB5A8B4AA893F3ADFD48E8ACEBC669}
Invoking 'c:\usr\wbin\exiftool.exe -DateTimeOriginal S:\powershell\test\foobar.cr2'
Date/Time Original              : 2019:12:25 16:36:30

Actual Behaviour

When run via the debugger (F5 in VScode) the script hangs:

'exiftool' is 'c:\usr\wbin\exiftool.exe' (version 12.2.1.0) {MD5=4ECB5A8B4AA893F3ADFD48E8ACEBC669}
Invoking 'c:\usr\wbin\exiftool.exe -DateTimeOriginal S:\powershell\test\foobar.cr2'

Here’s the version of exiftool.exe on my system:

exiftool.zip

Attached Logs

1614863299-c8495592-f210-48e1-a203-cc687e42687b1614861694455 - Copy.zip

[sba923]

Can you please confirm this (the dummy character) is fixed with version 2022.5.0 of the extension and PSReadLine 2.2.5?

Yes indeed it is!

Good news! This means I’ll no longer need to use the workaround

$result = '' | & $exiftool @exiftool_args

and will be able to use the standard construct instead:

$result = & $exiftool @exiftool_args

Thanks again for the fix. I’ve been patient 😜.

[SeeminglyScience]

My guess is that whatever way they check to see if they should expect input is getting triggered by the fact that we have Console.ReadKey pending in a different thread. So they see for whatever reason that something is expecting input, and then it assumes it needs to take input, so it waits until it does?

Purely guess work until we change up how readkey works, but I’m fairly confident.