diff --git a/eng/pipelines/templates/jobs/analyze.yml b/eng/pipelines/templates/jobs/analyze.yml
index 4fbe04198a..d3feee17c5 100644
--- a/eng/pipelines/templates/jobs/analyze.yml
+++ b/eng/pipelines/templates/jobs/analyze.yml
@@ -38,6 +38,12 @@ jobs:
 
   - template: /eng/common/pipelines/templates/steps/save-package-properties.yml
 
+  - task: PowerShell@2
+    displayName: Validate pipeline diagnostic parsers
+    inputs:
+      pwsh: true
+      filePath: $(Build.SourcesDirectory)/eng/scripts/tests/Test-Diagnostics.ps1
+
   # Always skip audit. Audit requires contact with restricted endpoints and is
   # excluded from use in internal builds. Instead, teams must check on the state
   # of the Audit in GitHub Actions.
@@ -53,6 +59,13 @@ jobs:
         -Audit:$false
         -Deny
 
-  - template: /eng/common/pipelines/templates/steps/check-spelling.yml
-    parameters:
-      ContinueOnError: false
+  - ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
+    - template: /eng/common/pipelines/templates/steps/create-authenticated-npmrc.yml
+
+    - task: PowerShell@2
+      displayName: Check spelling (cspell)
+      condition: and(succeeded(), ne(variables['Skip.SpellCheck'],'true'))
+      inputs:
+        pwsh: true
+        filePath: $(Build.SourcesDirectory)/eng/scripts/Check-Spelling.ps1
+        arguments: -ExitWithError
diff --git a/eng/scripts/Analyze-Code.ps1 b/eng/scripts/Analyze-Code.ps1
index 93ae098c42..b624abfaf8 100755
--- a/eng/scripts/Analyze-Code.ps1
+++ b/eng/scripts/Analyze-Code.ps1
@@ -63,17 +63,28 @@ $packagesToAnalyze = Get-CargoSelectedPackages `
   -PackageInfoDirectory $packageInfoPath
 $workspaceManifestPath = [System.IO.Path]::Combine($RepoRoot, 'Cargo.toml')
 $packageArgs = if ($PackageName -or $ManifestDir) {
-  '--package ' + ($packagesToAnalyze.name -join ' --package ')
+  @($packagesToAnalyze.name | ForEach-Object { '--package'; $_ })
 }
+$packageArgsString = $packageArgs -join ' '
 
 if ($Audit) {
   Invoke-LoggedCommand "cargo audit" -GroupOutput
 }
 
-Invoke-LoggedCommand "cargo check --manifest-path sdk/core/azure_core/Cargo.toml $packageArgs --all-features --all-targets --keep-going" -GroupOutput
+[void](Invoke-CargoCommandWithDiagnostics `
+  -ArgumentList (@(
+    'check',
+    '--manifest-path',
+    'sdk/core/azure_core/Cargo.toml'
+  ) + $packageArgs + @(
+    '--all-features',
+    '--all-targets',
+    '--keep-going'
+  )) `
+  -GroupOutput)
 
 if ($packageArgs) {
-  Invoke-LoggedCommand "cargo fmt --manifest-path '$workspaceManifestPath' $packageArgs -- --check" -GroupOutput
+  Invoke-LoggedCommand "cargo fmt --manifest-path '$workspaceManifestPath' $packageArgsString -- --check" -GroupOutput
 }
 else {
   Invoke-LoggedCommand "cargo fmt --manifest-path '$workspaceManifestPath' --all -- --check" -GroupOutput
@@ -81,13 +92,33 @@ else {
 
 Invoke-LoggedCommand "taplo format --check"
 
-Invoke-LoggedCommand "cargo clippy --manifest-path '$workspaceManifestPath' $packageArgs --all-features --all-targets --keep-going --no-deps" -GroupOutput
+[void](Invoke-CargoCommandWithDiagnostics `
+  -ArgumentList (@(
+    'clippy',
+    '--manifest-path',
+    $workspaceManifestPath
+  ) + $packageArgs + @(
+    '--all-features',
+    '--all-targets',
+    '--keep-going',
+    '--no-deps'
+  )) `
+  -GroupOutput)
 
 if ($Deny) {
   Invoke-LoggedCommand "cargo deny --manifest-path '$workspaceManifestPath' --all-features check bans licenses sources" -GroupOutput
 }
 
-Invoke-LoggedCommand "cargo doc --manifest-path '$workspaceManifestPath' $packageArgs --no-deps --all-features" -GroupOutput
+[void](Invoke-CargoCommandWithDiagnostics `
+  -ArgumentList (@(
+    'doc',
+    '--manifest-path',
+    $workspaceManifestPath
+  ) + $packageArgs + @(
+    '--no-deps',
+    '--all-features'
+  )) `
+  -GroupOutput)
 
 # Verify package dependencies and keywords
 $verifyDependenciesScript = ([System.IO.Path]::Combine($RepoRoot, 'eng', 'scripts', 'verify-dependencies.rs'))
diff --git a/eng/scripts/Build-Crates.ps1 b/eng/scripts/Build-Crates.ps1
index a7cfd5709c..9f94edafc3 100755
--- a/eng/scripts/Build-Crates.ps1
+++ b/eng/scripts/Build-Crates.ps1
@@ -29,5 +29,13 @@ else {
 }
 
 foreach ($path in $manifestPath) {
-  Invoke-LoggedCommand "cargo build --manifest-path '$path' --keep-going --all-features" -GroupOutput
+  [void](Invoke-CargoCommandWithDiagnostics `
+    -ArgumentList @(
+      'build',
+      '--manifest-path',
+      $path,
+      '--keep-going',
+      '--all-features'
+    ) `
+    -GroupOutput)
 }
diff --git a/eng/scripts/Check-Spelling.ps1 b/eng/scripts/Check-Spelling.ps1
new file mode 100644
index 0000000000..7207c7cf85
--- /dev/null
+++ b/eng/scripts/Check-Spelling.ps1
@@ -0,0 +1,85 @@
+#!/usr/bin/env pwsh
+
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+#Requires -Version 7.0
+[CmdletBinding()]
+param(
+  [string]$CspellConfigPath = ([System.IO.Path]::Combine($PSScriptRoot, '..', '..', '.vscode', 'cspell.json')),
+  [string]$SpellCheckRoot = ([System.IO.Path]::Combine($PSScriptRoot, '..', '..')),
+  [switch]$ExitWithError,
+  [string]$SourceCommittish = $env:SYSTEM_PULLREQUEST_SOURCECOMMITID,
+  [string]$TargetCommittish = ("origin/$($env:SYSTEM_PULLREQUEST_TARGETBRANCH)" -replace 'refs/heads/')
+)
+
+$ErrorActionPreference = 'Stop'
+Set-StrictMode -Version 2.0
+
+. ([System.IO.Path]::Combine($PSScriptRoot, '..', 'common', 'scripts', 'common.ps1'))
+. ([System.IO.Path]::Combine($PSScriptRoot, 'shared', 'common.ps1'))
+
+if (!(Test-Path -Path $CspellConfigPath -PathType Leaf)) {
+  Write-PipelineIssue -Type error -Message "Could not locate CSpell config file '$CspellConfigPath'."
+  exit 1
+}
+
+$getChangedFilesScript = ([System.IO.Path]::Combine($PSScriptRoot, '..', 'common', 'scripts', 'get-changedfiles.ps1'))
+$invokeCspellScript = ([System.IO.Path]::Combine($PSScriptRoot, '..', 'common', 'spelling', 'Invoke-Cspell.ps1'))
+$changedFiles = @(
+  & $getChangedFilesScript `
+    -SourceCommittish $SourceCommittish `
+    -TargetCommittish $TargetCommittish |
+    ForEach-Object { Resolve-Path -Path $_ }
+)
+
+Write-Host "Git detected $($changedFiles.Count) changed file(s). Files checked by CSpell may exclude files according to cspell.json."
+if ($changedFiles.Count -eq 0) {
+  Write-Host 'No changes detected.'
+  exit 0
+}
+
+$spellingOutput = @(
+  & $invokeCspellScript `
+    -CSpellConfigPath $CspellConfigPath `
+    -SpellCheckRoot $SpellCheckRoot `
+    -FileList $changedFiles.Path
+)
+$cspellExitCode = $LASTEXITCODE
+$issueBudget = New-PipelineIssueBudget
+$parsedIssues = 0
+
+foreach ($line in $spellingOutput) {
+  $text = "$line"
+  Write-Host $text
+  $issue = ConvertFrom-CSpellIssue $text
+  if ($issue) {
+    Write-BudgetedPipelineIssue `
+      -Budget $issueBudget `
+      -Type $(if ($ExitWithError) { 'error' } else { 'warning' }) `
+      -Message $issue.Message `
+      -SourcePath $issue.SourcePath `
+      -LineNumber $issue.LineNumber `
+      -ColumnNumber $issue.ColumnNumber `
+      -Code 'cspell'
+    $parsedIssues++
+  }
+}
+
+Complete-PipelineIssueBudget $issueBudget
+
+if ($parsedIssues -gt 0) {
+  Write-Host 'Spelling errors detected. To correct false positives or learn about spell checking, see https://aka.ms/azsdk/engsys/spellcheck.'
+  if ($ExitWithError) {
+    exit 1
+  }
+}
+elseif ($cspellExitCode -ne 0) {
+  Write-PipelineIssue -Type error -Message "CSpell exited with code $cspellExitCode. This may indicate a configuration or tool failure."
+  exit $cspellExitCode
+}
+else {
+  Write-Host 'No spelling errors detected.'
+}
+
+exit 0
diff --git a/eng/scripts/Test-Packages.ps1 b/eng/scripts/Test-Packages.ps1
index 6c516a5e97..1955742f4b 100755
--- a/eng/scripts/Test-Packages.ps1
+++ b/eng/scripts/Test-Packages.ps1
@@ -22,36 +22,43 @@ $cargoFeatureArgs = if ($FeatureSet -eq 'All') { @('--all-features') } else { @(
 # Helper function to run cargo test, capturing JSON output only when the active
 # toolchain supports `--format json -Z unstable-options`.
 function Invoke-CargoTest (
-  [string]$TestParams,
+  [string[]]$TestParams,
   [string]$PackageName,
   [string]$ManifestPath,
-  [string]$OutputFile
+  [string]$OutputFile,
+  [switch]$DisableJsonOutput
 ) {
   Write-Host "Running tests for $PackageName"
-  $commandParts = @('cargo', 'test', $TestParams, '--manifest-path', $ManifestPath) + $cargoFeatureArgs + @('--no-fail-fast')
-  $command = $commandParts -join ' '
+  $commandArgs = @('test') + $TestParams + @('--manifest-path', $ManifestPath) + $cargoFeatureArgs + @('--no-fail-fast')
+  $captureJson = $usesJsonTestOutput -and !$DisableJsonOutput
 
-  if ($usesJsonTestOutput) {
-    $result = Invoke-LoggedCommand `
-      "$command -- --format json -Z unstable-options" `
+  if ($captureJson) {
+    $result = Invoke-CargoCommandWithDiagnostics `
+      -ArgumentList ($commandArgs + @('--', '--format', 'json', '-Z', 'unstable-options')) `
       -GroupOutput `
-      -DoNotExitOnFailedExitCode
+      -DoNotExitOnFailedExitCode `
+      -ParseJsonTestOutput `
+      -TestOutputFile $OutputFile
 
     LogGroupStart 'Test result JSON'
-    $result | Tee-Object -FilePath $OutputFile
+    Get-Content $OutputFile | Write-Host
     LogGroupEnd
   }
   else {
-    Invoke-LoggedCommand $command -GroupOutput -DoNotExitOnFailedExitCode
+    $result = Invoke-CargoCommandWithDiagnostics `
+      -ArgumentList $commandArgs `
+      -GroupOutput `
+      -DoNotExitOnFailedExitCode `
+      -ParseHumanTestOutput
   }
 
-  if ($LASTEXITCODE) {
+  if ($result.ExitCode) {
     $message = "Tests failed for $PackageName."
-    if ($usesJsonTestOutput) {
+    if ($captureJson) {
       $message += " For more information see the pipeline Tests tab."
     }
-    LogError $message
-    exit $LASTEXITCODE
+    Write-Host $message
+    exit $result.ExitCode
   }
 }
 
@@ -113,8 +120,9 @@ foreach ($package in $packagesToTest) {
 
   Write-Host "`n`nTesting package: '$($package.Name)'`n"
 
-  $buildCommand = (@('cargo', 'build') + $cargoFeatureArgs + @('--keep-going')) -join ' '
-  Invoke-LoggedCommand $buildCommand -GroupOutput
+  [void](Invoke-CargoCommandWithDiagnostics `
+    -ArgumentList (@('build') + $cargoFeatureArgs + @('--keep-going')) `
+    -GroupOutput)
   Write-Host "`n`n"
 
   $manifestPath = [System.IO.Path]::Combine($packageDirectory, 'Cargo.toml')
@@ -122,20 +130,23 @@ foreach ($package in $packagesToTest) {
 
   $docTestOutput = ([System.IO.Path]::Combine($testResultsDir, "$($package.Name)-doctest-$timestamp.json"))
   Invoke-CargoTest `
-    -TestParams "--doc" `
+    -TestParams @('--doc') `
     -PackageName $package.Name `
     -ManifestPath $manifestPath `
     -OutputFile $docTestOutput
 
   $allTargetsOutput = ([System.IO.Path]::Combine($testResultsDir, "$($package.Name)-alltargets-$timestamp.json"))
   Invoke-CargoTest `
-    -TestParams "--lib --bins --tests --examples" `
+    -TestParams @('--lib', '--bins', '--tests', '--examples') `
     -PackageName $package.Name `
     -ManifestPath $manifestPath `
     -OutputFile $allTargetsOutput
 
-  $benchCommand = (@('cargo', 'test', '--benches', '--manifest-path', $manifestPath) + $cargoFeatureArgs + @('--no-fail-fast')) -join ' '
-  Invoke-LoggedCommand $benchCommand -GroupOutput
+  Invoke-CargoTest `
+    -TestParams @('--benches') `
+    -PackageName $package.Name `
+    -ManifestPath $manifestPath `
+    -DisableJsonOutput
 
   $cleanupScript = ([System.IO.Path]::Combine($packageDirectory, 'Test-Cleanup.ps1'))
   if (Test-Path $cleanupScript) {
diff --git a/eng/scripts/shared/Cargo.ps1 b/eng/scripts/shared/Cargo.ps1
index 79e1151243..c759d807b8 100644
--- a/eng/scripts/shared/Cargo.ps1
+++ b/eng/scripts/shared/Cargo.ps1
@@ -2,6 +2,10 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
+if (!(Get-Command New-PipelineIssueBudget -ErrorAction SilentlyContinue)) {
+  . ([System.IO.Path]::Combine($PSScriptRoot, 'Diagnostics.ps1'))
+}
+
 function Get-ActiveRustToolchain(
   [string]$ExecutePath
 ) {
@@ -31,6 +35,256 @@ function Test-IsNightlyRustToolchain(
   return (Get-ResolvedRustToolchain -Toolchain $Toolchain -ExecutePath $ExecutePath) -match '^nightly(?:$|[-])'
 }
 
+function Get-CargoArgumentsWithJsonMessages([string[]]$ArgumentList) {
+  if ($ArgumentList -match '^--message-format(?:=|$)') {
+    return $ArgumentList
+  }
+
+  $separatorIndex = [Array]::IndexOf($ArgumentList, '--')
+  if ($separatorIndex -lt 0) {
+    return @($ArgumentList) + @('--message-format=json')
+  }
+
+  return @($ArgumentList[0..($separatorIndex - 1)]) +
+    @('--message-format=json') +
+    @($ArgumentList[$separatorIndex..($ArgumentList.Count - 1)])
+}
+
+function Get-JsonPropertyValue(
+  $Object,
+  [string]$Name
+) {
+  if (!$Object) {
+    return $null
+  }
+
+  $property = $Object.PSObject.Properties[$Name]
+  if ($property) {
+    return $property.Value
+  }
+  return $null
+}
+
+function Get-RustTestFailuresFromOutput([string[]]$Output) {
+  $failures = @()
+  $name = $null
+  $details = [System.Collections.Generic.List[string]]::new()
+
+  foreach ($line in $Output) {
+    if ($line -match '^---- (.+) stdout ----$') {
+      if ($name) {
+        $failures += [pscustomobject]@{
+          Name = $name
+          Output = ($details -join [Environment]::NewLine).Trim()
+        }
+      }
+      $name = $Matches[1]
+      $details.Clear()
+      continue
+    }
+
+    if ($name -and $line -eq 'failures:') {
+      $failures += [pscustomobject]@{
+        Name = $name
+        Output = ($details -join [Environment]::NewLine).Trim()
+      }
+      $name = $null
+      $details.Clear()
+      continue
+    }
+
+    if ($name) {
+      $details.Add($line)
+    }
+  }
+
+  if ($name) {
+    $failures += [pscustomobject]@{
+      Name = $name
+      Output = ($details -join [Environment]::NewLine).Trim()
+    }
+  }
+
+  return $failures
+}
+
+function Write-CargoCompilerDiagnostic(
+  $CargoMessage,
+  $IssueBudget
+) {
+  $diagnostic = Get-JsonPropertyValue $CargoMessage 'message'
+  $renderedValue = Get-JsonPropertyValue $diagnostic 'rendered'
+  $messageValue = Get-JsonPropertyValue $diagnostic 'message'
+  $rendered = if ($renderedValue) { "$renderedValue".TrimEnd() } else { "$messageValue" }
+  Write-Host $rendered
+
+  if ((Get-JsonPropertyValue $diagnostic 'level') -ne 'error') {
+    return $false
+  }
+
+  $spans = @(Get-JsonPropertyValue $diagnostic 'spans')
+  $primarySpan = @($spans | Where-Object { Get-JsonPropertyValue $_ 'is_primary' } | Select-Object -First 1)
+  $sourcePath = $null
+  $lineNumber = 0
+  $columnNumber = 0
+  if ($primarySpan.Count -gt 0) {
+    $sourcePath = Get-JsonPropertyValue $primarySpan[0] 'file_name'
+    $lineNumber = Get-JsonPropertyValue $primarySpan[0] 'line_start'
+    $columnNumber = Get-JsonPropertyValue $primarySpan[0] 'column_start'
+  }
+
+  $diagnosticCode = Get-JsonPropertyValue $diagnostic 'code'
+  $code = Get-JsonPropertyValue $diagnosticCode 'code'
+  Write-BudgetedPipelineIssue `
+    -Budget $IssueBudget `
+    -Type error `
+    -Message $rendered `
+    -SourcePath $sourcePath `
+    -LineNumber $lineNumber `
+    -ColumnNumber $columnNumber `
+    -Code $code
+  return $true
+}
+
+function Write-RustTestFailure(
+  [string]$Name,
+  [string]$Output,
+  $IssueBudget
+) {
+  $message = "Test '$Name' failed."
+  if ($Output) {
+    $message += [Environment]::NewLine + $Output.Trim()
+  }
+  Write-BudgetedPipelineIssue -Budget $IssueBudget -Type error -Message $message
+}
+
+function Write-RustJsonTestEvent(
+  $TestEvent,
+  $IssueBudget
+) {
+  if ((Get-JsonPropertyValue $TestEvent 'type') -ne 'test' -or (Get-JsonPropertyValue $TestEvent 'event') -ne 'failed') {
+    return $false
+  }
+
+  $testOutput = @(
+    Get-JsonPropertyValue $TestEvent 'message'
+    Get-JsonPropertyValue $TestEvent 'reason'
+    Get-JsonPropertyValue $TestEvent 'stdout'
+  ) |
+    Where-Object { $_ } |
+    ForEach-Object { "$_".Trim() }
+  Write-RustTestFailure `
+    -Name (Get-JsonPropertyValue $TestEvent 'name') `
+    -Output ($testOutput -join [Environment]::NewLine) `
+    -IssueBudget $IssueBudget
+  return $true
+}
+
+function Invoke-CargoCommandWithDiagnostics {
+  [CmdletBinding()]
+  param(
+    [Parameter(Mandatory = $true)]
+    [string[]]$ArgumentList,
+    [switch]$GroupOutput,
+    [switch]$DoNotExitOnFailedExitCode,
+    [switch]$ParseJsonTestOutput,
+    [switch]$ParseHumanTestOutput,
+    [string]$TestOutputFile,
+    [int]$MaximumIssues = 50
+  )
+
+  $cargoArguments = Get-CargoArgumentsWithJsonMessages $ArgumentList
+  $command = "cargo $($cargoArguments -join ' ')"
+  $startTime = Get-Date
+  $issueBudget = New-PipelineIssueBudget -Maximum $MaximumIssues
+  $humanTestOutput = [System.Collections.Generic.List[string]]::new()
+  $jsonTestOutput = [System.Collections.Generic.List[string]]::new()
+
+  if ($GroupOutput) {
+    LogGroupStart $command
+  }
+  else {
+    Write-Host "> $command"
+  }
+
+  try {
+    & cargo @cargoArguments 2>&1 | ForEach-Object {
+      $line = "$_"
+      $json = $null
+      if ($line.TrimStart().StartsWith('{')) {
+        try {
+          $json = $line | ConvertFrom-Json -Depth 100 -ErrorAction Stop
+        }
+        catch {
+          $json = $null
+        }
+      }
+
+      $reason = Get-JsonPropertyValue $json 'reason'
+      $type = Get-JsonPropertyValue $json 'type'
+      $event = Get-JsonPropertyValue $json 'event'
+      if ($reason -eq 'compiler-message') {
+        [void](Write-CargoCompilerDiagnostic -CargoMessage $json -IssueBudget $issueBudget)
+      }
+      elseif ($ParseJsonTestOutput -and $type -and $event) {
+        $jsonTestOutput.Add($line)
+        [void](Write-RustJsonTestEvent -TestEvent $json -IssueBudget $issueBudget)
+      }
+      elseif ($reason) {
+        # Cargo artifact and build-script records are intentionally omitted.
+      }
+      else {
+        Write-Host $line
+        if ($ParseHumanTestOutput) {
+          $humanTestOutput.Add($line)
+        }
+      }
+    }
+    $exitCode = $LASTEXITCODE
+  }
+  finally {
+    if ($GroupOutput) {
+      LogGroupEnd
+    }
+  }
+
+  if ($TestOutputFile) {
+    [System.IO.File]::WriteAllLines($TestOutputFile, $jsonTestOutput)
+  }
+
+  if ($exitCode -ne 0 -and $ParseHumanTestOutput) {
+    foreach ($failure in (Get-RustTestFailuresFromOutput $humanTestOutput)) {
+      Write-RustTestFailure -Name $failure.Name -Output $failure.Output -IssueBudget $issueBudget
+    }
+  }
+
+  $duration = (Get-Date) - $startTime
+  if ($exitCode -ne 0) {
+    if ($issueBudget.Emitted -eq 0) {
+      Write-BudgetedPipelineIssue `
+        -Budget $issueBudget `
+        -Type error `
+        -Message "Command failed to execute ($duration): $command"
+    }
+    Write-Host "Command failed to execute ($duration): $command"
+  }
+  else {
+    Write-Host "Command succeeded ($duration)`n"
+  }
+
+  Complete-PipelineIssueBudget $issueBudget
+
+  if ($exitCode -ne 0 -and !$DoNotExitOnFailedExitCode) {
+    exit $exitCode
+  }
+
+  return [pscustomobject]@{
+    ExitCode = $exitCode
+    IssueCount = $issueBudget.Emitted
+    SuppressedIssueCount = $issueBudget.Suppressed
+  }
+}
+
 function Get-CargoMetadata() {
   cargo metadata --no-deps --format-version 1 --manifest-path "$RepoRoot/Cargo.toml" | ConvertFrom-Json -Depth 100 -AsHashtable
 }
diff --git a/eng/scripts/shared/Diagnostics.ps1 b/eng/scripts/shared/Diagnostics.ps1
new file mode 100644
index 0000000000..bfda114c40
--- /dev/null
+++ b/eng/scripts/shared/Diagnostics.ps1
@@ -0,0 +1,169 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+function ConvertTo-AzDevOpsLoggingValue(
+  [string]$Value,
+  [switch]$Property
+) {
+  $escaped = $Value.Replace('%', '%AZP25').Replace("`r", '%0D').Replace("`n", '%0A')
+  if ($Property) {
+    $escaped = $escaped.Replace(';', '%3B').Replace(']', '%5D')
+  }
+  return $escaped
+}
+
+function ConvertTo-GitHubLoggingValue(
+  [string]$Value,
+  [switch]$Property
+) {
+  $escaped = $Value.Replace('%', '%25').Replace("`r", '%0D').Replace("`n", '%0A')
+  if ($Property) {
+    $escaped = $escaped.Replace(':', '%3A').Replace(',', '%2C')
+  }
+  return $escaped
+}
+
+function Get-RepositoryRelativePath([string]$Path) {
+  if (!$Path) {
+    return $null
+  }
+
+  try {
+    $fullPath = if ([System.IO.Path]::IsPathRooted($Path)) {
+      [System.IO.Path]::GetFullPath($Path)
+    }
+    else {
+      [System.IO.Path]::GetFullPath(([System.IO.Path]::Combine($RepoRoot, $Path)))
+    }
+    $relativePath = [System.IO.Path]::GetRelativePath(
+      [System.IO.Path]::GetFullPath($RepoRoot),
+      $fullPath
+    )
+
+    if ([System.IO.Path]::IsPathRooted($relativePath) -or $relativePath -eq '..' -or $relativePath.StartsWith("../") -or $relativePath.StartsWith("..\"))
+    {
+      return $null
+    }
+
+    return $relativePath.Replace('\', '/')
+  }
+  catch {
+    return $null
+  }
+}
+
+function ConvertFrom-CSpellIssue([string]$Line) {
+  if ($Line -notmatch '^(?<file>.+):(?<line>\d+):(?<column>\d+)\s+-\s+(?<message>.+)$') {
+    return $null
+  }
+
+  return [pscustomobject]@{
+    SourcePath = $Matches.file
+    LineNumber = [int]$Matches.line
+    ColumnNumber = [int]$Matches.column
+    Message = $Matches.message
+  }
+}
+
+function Write-PipelineIssue(
+  [ValidateSet('error', 'warning')]
+  [string]$Type,
+  [string]$Message,
+  [string]$SourcePath,
+  [int]$LineNumber,
+  [int]$ColumnNumber,
+  [string]$Code
+) {
+  $relativePath = Get-RepositoryRelativePath $SourcePath
+
+  if (Test-SupportsDevOpsLogging) {
+    $properties = "type=$Type;"
+    if ($relativePath) {
+      $properties += "sourcepath=$(ConvertTo-AzDevOpsLoggingValue $relativePath -Property);"
+      if ($LineNumber -gt 0) {
+        $properties += "linenumber=$LineNumber;"
+      }
+      if ($ColumnNumber -gt 0) {
+        $properties += "columnnumber=$ColumnNumber;"
+      }
+    }
+    if ($Code) {
+      $properties += "code=$(ConvertTo-AzDevOpsLoggingValue $Code -Property);"
+    }
+
+    Write-Host "##vso[task.logissue $properties]$(ConvertTo-AzDevOpsLoggingValue $Message)"
+  }
+  elseif (Test-SupportsGitHubLogging) {
+    $properties = @()
+    if ($relativePath) {
+      $properties += "file=$(ConvertTo-GitHubLoggingValue $relativePath -Property)"
+      if ($LineNumber -gt 0) {
+        $properties += "line=$LineNumber"
+      }
+      if ($ColumnNumber -gt 0) {
+        $properties += "col=$ColumnNumber"
+      }
+    }
+    if ($Code) {
+      $properties += "title=$(ConvertTo-GitHubLoggingValue $Code -Property)"
+    }
+
+    $propertyText = if ($properties.Count -gt 0) { " $($properties -join ',')" } else { '' }
+    Write-Host "::$Type$propertyText::$(ConvertTo-GitHubLoggingValue $Message)"
+  }
+  elseif ($Type -eq 'error') {
+    if ($relativePath) {
+      Write-Host "[$relativePath`:$LineNumber`:$ColumnNumber] $Message" -ForegroundColor Red
+    }
+    else {
+      Write-Host $Message -ForegroundColor Red
+    }
+  }
+  else {
+    if ($relativePath) {
+      Write-Host "[$relativePath`:$LineNumber`:$ColumnNumber] $Message" -ForegroundColor Yellow
+    }
+    else {
+      Write-Host $Message -ForegroundColor Yellow
+    }
+  }
+}
+
+function New-PipelineIssueBudget([int]$Maximum = 50) {
+  return [pscustomobject]@{
+    Maximum = $Maximum
+    Emitted = 0
+    Suppressed = 0
+  }
+}
+
+function Write-BudgetedPipelineIssue(
+  $Budget,
+  [ValidateSet('error', 'warning')]
+  [string]$Type,
+  [string]$Message,
+  [string]$SourcePath,
+  [int]$LineNumber,
+  [int]$ColumnNumber,
+  [string]$Code
+) {
+  if ($Budget.Emitted -ge $Budget.Maximum) {
+    $Budget.Suppressed++
+    return
+  }
+
+  Write-PipelineIssue `
+    -Type $Type `
+    -Message $Message `
+    -SourcePath $SourcePath `
+    -LineNumber $LineNumber `
+    -ColumnNumber $ColumnNumber `
+    -Code $Code
+  $Budget.Emitted++
+}
+
+function Complete-PipelineIssueBudget($Budget) {
+  if ($Budget.Suppressed -gt 0) {
+    Write-Host "Suppressed $($Budget.Suppressed) additional pipeline issue(s) after reaching the $($Budget.Maximum)-issue limit. See the task log for complete output."
+  }
+}
diff --git a/eng/scripts/shared/common.ps1 b/eng/scripts/shared/common.ps1
index 0f60880e33..adaf832153 100644
--- a/eng/scripts/shared/common.ps1
+++ b/eng/scripts/shared/common.ps1
@@ -2,4 +2,5 @@
 # Licensed under the MIT License.
 
 . ([System.IO.Path]::Combine($PSScriptRoot, 'Process.ps1'))
+. ([System.IO.Path]::Combine($PSScriptRoot, 'Diagnostics.ps1'))
 . ([System.IO.Path]::Combine($PSScriptRoot, 'Cargo.ps1'))
diff --git a/eng/scripts/tests/Test-Diagnostics.ps1 b/eng/scripts/tests/Test-Diagnostics.ps1
new file mode 100644
index 0000000000..34a0fefb48
--- /dev/null
+++ b/eng/scripts/tests/Test-Diagnostics.ps1
@@ -0,0 +1,151 @@
+#!/usr/bin/env pwsh
+
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+#Requires -Version 7.0
+
+$ErrorActionPreference = 'Stop'
+Set-StrictMode -Version 2.0
+
+$global:RepoRoot = [System.IO.Path]::GetFullPath(([System.IO.Path]::Combine($PSScriptRoot, '..', '..', '..')))
+. ([System.IO.Path]::Combine($RepoRoot, 'eng', 'common', 'scripts', 'logging.ps1'))
+. ([System.IO.Path]::Combine($RepoRoot, 'eng', 'scripts', 'shared', 'Diagnostics.ps1'))
+. ([System.IO.Path]::Combine($RepoRoot, 'eng', 'scripts', 'shared', 'Cargo.ps1'))
+
+function Assert-Equal($Expected, $Actual, [string]$Description) {
+  if ($Expected -ne $Actual) {
+    throw "$Description`nExpected: $Expected`nActual:   $Actual"
+  }
+}
+
+function Assert-Contains([string]$Expected, [string[]]$Actual, [string]$Description) {
+  if (!($Actual | Where-Object { "$_".Contains($Expected) })) {
+    throw "$Description`nExpected output containing: $Expected`nActual output:`n$($Actual -join [Environment]::NewLine)"
+  }
+}
+
+Assert-Equal `
+  '100%AZP25%3B%5D%0D%0A' `
+  (ConvertTo-AzDevOpsLoggingValue "100%;]`r`n" -Property) `
+  'Azure DevOps properties should be escaped.'
+
+$cargoArgs = Get-CargoArgumentsWithJsonMessages @('test', '--all-features', '--', '--nocapture')
+Assert-Equal `
+  'test --all-features --message-format=json -- --nocapture' `
+  ($cargoArgs -join ' ') `
+  'Cargo JSON message format should be inserted before test-binary arguments.'
+
+$humanFailures = @(Get-RustTestFailuresFromOutput @(
+    'running 1 test',
+    'test tests::fails ... FAILED',
+    '',
+    'failures:',
+    '',
+    '---- tests::fails stdout ----',
+    'thread ''tests::fails'' panicked at src/lib.rs:10:5:',
+    'assertion failed',
+    '',
+    'failures:',
+    '    tests::fails'
+  ))
+Assert-Equal 1 $humanFailures.Count 'One human-format test failure should be parsed.'
+Assert-Equal 'tests::fails' $humanFailures[0].Name 'The failed test name should be parsed.'
+Assert-Contains 'assertion failed' @($humanFailures[0].Output) 'The failed test output should be retained.'
+
+$unixSpellingIssue = ConvertFrom-CSpellIssue 'sdk/example.rs:8:14 - Unknown word (azur)'
+Assert-Equal 'sdk/example.rs' $unixSpellingIssue.SourcePath 'A Unix CSpell path should be parsed.'
+Assert-Equal 8 $unixSpellingIssue.LineNumber 'A CSpell line should be parsed.'
+Assert-Equal 14 $unixSpellingIssue.ColumnNumber 'A CSpell column should be parsed.'
+
+$windowsSpellingIssue = ConvertFrom-CSpellIssue 'C:\agent\_work\1\s\sdk\example.rs:9:3 - Unknown word (azur)'
+Assert-Equal 'C:\agent\_work\1\s\sdk\example.rs' $windowsSpellingIssue.SourcePath 'A Windows CSpell path should be parsed.'
+
+$oldTeamProjectId = $env:SYSTEM_TEAMPROJECTID
+try {
+  $env:SYSTEM_TEAMPROJECTID = 'test'
+  $issueOutput = @(
+    (& {
+        Write-PipelineIssue `
+          -Type error `
+          -Message "error[E0001]`nhelp: fix 100%" `
+          -SourcePath ([System.IO.Path]::Combine($RepoRoot, 'sdk', 'example.rs')) `
+          -LineNumber 12 `
+          -ColumnNumber 7 `
+          -Code 'E0001'
+      } 6>&1) | ForEach-Object { "$_" }
+  )
+
+  Assert-Equal 1 $issueOutput.Count 'One Azure DevOps logging command should be emitted.'
+  Assert-Contains 'sourcepath=sdk/example.rs;' $issueOutput 'The repository-relative source path should be included.'
+  Assert-Contains 'linenumber=12;columnnumber=7;code=E0001;' $issueOutput 'The source location and diagnostic code should be included.'
+  Assert-Contains 'error[E0001]%0Ahelp: fix 100%AZP25' $issueOutput 'The multiline diagnostic body should be escaped.'
+
+  $budget = New-PipelineIssueBudget -Maximum 2
+  $budgetOutput = @(
+    (& {
+        1..3 | ForEach-Object {
+          Write-BudgetedPipelineIssue -Budget $budget -Type error -Message "failure $_"
+        }
+        Complete-PipelineIssueBudget $budget
+      } 6>&1) | ForEach-Object { "$_" }
+  )
+
+  Assert-Equal 2 $budget.Emitted 'The issue budget should emit only its maximum.'
+  Assert-Equal 1 $budget.Suppressed 'The issue budget should count suppressed issues.'
+  Assert-Contains 'Suppressed 1 additional pipeline issue' $budgetOutput 'Suppressed issues should be summarized.'
+
+  $cargoMessage = @'
+{
+  "reason": "compiler-message",
+  "message": {
+    "rendered": "error[E0308]: mismatched types\n  --> sdk/example.rs:4:9\nhelp: use the expected type\n",
+    "message": "mismatched types",
+    "level": "error",
+    "code": { "code": "E0308" },
+    "spans": [
+      {
+        "file_name": "sdk/example.rs",
+        "line_start": 4,
+        "column_start": 9,
+        "is_primary": true
+      }
+    ]
+  }
+}
+'@ | ConvertFrom-Json -Depth 100
+  $cargoBudget = New-PipelineIssueBudget
+  $cargoOutput = @(
+    (& {
+        [void](Write-CargoCompilerDiagnostic -CargoMessage $cargoMessage -IssueBudget $cargoBudget)
+      } 6>&1) | ForEach-Object { "$_" }
+  )
+
+  Assert-Equal 1 $cargoBudget.Emitted 'An error-level Cargo diagnostic should emit one issue.'
+  Assert-Contains 'sourcepath=sdk/example.rs;linenumber=4;columnnumber=9;code=E0308;' $cargoOutput 'Cargo spans should map to issue metadata.'
+  Assert-Contains 'help: use the expected type' $cargoOutput 'The complete rendered Cargo diagnostic should be retained.'
+
+  $testEvent = @'
+{
+  "type": "test",
+  "event": "failed",
+  "name": "tests::fails",
+  "stdout": "thread 'tests::fails' panicked at src/lib.rs:10:5:\nassertion failed"
+}
+'@ | ConvertFrom-Json
+  $testBudget = New-PipelineIssueBudget
+  $testOutput = @(
+    (& {
+        [void](Write-RustJsonTestEvent -TestEvent $testEvent -IssueBudget $testBudget)
+      } 6>&1) | ForEach-Object { "$_" }
+  )
+
+  Assert-Equal 1 $testBudget.Emitted 'A failed JSON test event should emit one issue.'
+  Assert-Contains "Test 'tests::fails' failed." $testOutput 'The failed test name should be included.'
+  Assert-Contains 'assertion failed' $testOutput 'Captured test output should be included.'
+}
+finally {
+  $env:SYSTEM_TEAMPROJECTID = $oldTeamProjectId
+}
+
+Write-Host 'Diagnostic parser tests passed.'