Summary
Add-LinesToFile in PowerShell.MCP 1.11.0 intermittently fails when inserting a multi-line block into an existing file on Windows. The cmdlet prints the normal changed-line preview, then reports:
Unable to move the replacement file to the file to be replaced. The file to be replaced has retained its original name.
A subsequent read confirms the target file was not changed.
Environment
PowerShell.MCP: 1.11.0
PowerShell: 7.6.3 Core
OS: Microsoft Windows 10.0.26200
Platform: Win32NT
Module path: C:\Users\kingd\OneDrive\Documents\PowerShell\Modules\PowerShell.MCP\1.11.0\PowerShell.MCP.psd1
Workspace file path: F:\GitHub\McpServer\tests\Build.Tests\WarningSuppressionValidationTargetTests.cs
Failing operation
This failed while inserting a multi-line C# test method into an existing file:
Add-LinesToFile 'tests\Build.Tests\WarningSuppressionValidationTargetTests.cs' -LineNumber 217 -Content $var1
The command displayed a diff-like preview showing the inserted block at line 217, then emitted the replacement-file move error above. Running Show-TextFiles immediately afterward showed the original file unchanged.
A similar insert failure occurred earlier in the same session while inserting class constants into:
tests\Build.Tests\MigrationAssemblyObsoleteWarningTests.cs
Workaround that succeeded
Replacing the existing line with a block that included the original line worked:
Update-LinesInFile 'tests\Build.Tests\WarningSuppressionValidationTargetTests.cs' -LineRange 217 -Content $var1
Non-repro on a tiny file
A small temp-file insert succeeded, so this may be related to existing file size/state, path, locking, or replacement-file handling rather than all Add-LinesToFile -LineNumber calls:
$tempPath = Join-Path 'C:\tmp' ('psmcp-add-lines-repro-' + [Guid]::NewGuid().ToString('N') + '.txt')
Add-LinesToFile $tempPath -Content "line 1`r`nline 2`r`nline 3`r`n"
Add-LinesToFile $tempPath -LineNumber 2 -Content "inserted a`r`ninserted b`r`n"Expected
Add-LinesToFile -LineNumber should either atomically insert the lines or return a diagnostic with the underlying source/target temp paths and the original IO exception.
Actual
The cmdlet previews the intended change, then fails to move the replacement file over the original and leaves the target unchanged. The error does not expose enough path/exception detail to diagnose whether this is a lock, cross-volume move, temp path issue, retry problem, or another Windows filesystem condition.
Summary
Add-LinesToFileinPowerShell.MCP1.11.0 intermittently fails when inserting a multi-line block into an existing file on Windows. The cmdlet prints the normal changed-line preview, then reports:A subsequent read confirms the target file was not changed.
Environment
Failing operation
This failed while inserting a multi-line C# test method into an existing file:
The command displayed a diff-like preview showing the inserted block at line 217, then emitted the replacement-file move error above. Running
Show-TextFilesimmediately afterward showed the original file unchanged.A similar insert failure occurred earlier in the same session while inserting class constants into:
Workaround that succeeded
Replacing the existing line with a block that included the original line worked:
Non-repro on a tiny file
A small temp-file insert succeeded, so this may be related to existing file size/state, path, locking, or replacement-file handling rather than all
Add-LinesToFile -LineNumbercalls:Expected
Add-LinesToFile -LineNumbershould either atomically insert the lines or return a diagnostic with the underlying source/target temp paths and the original IO exception.Actual
The cmdlet previews the intended change, then fails to move the replacement file over the original and leaves the target unchanged. The error does not expose enough path/exception detail to diagnose whether this is a lock, cross-volume move, temp path issue, retry problem, or another Windows filesystem condition.