diff --git a/.github/actions/build-dotnet/Build-DotNetSolutionOrProject.ps1 b/.github/actions/build-dotnet/Build-DotNetSolutionOrProject.ps1
index e66b6f736..8c9c00625 100644
--- a/.github/actions/build-dotnet/Build-DotNetSolutionOrProject.ps1
+++ b/.github/actions/build-dotnet/Build-DotNetSolutionOrProject.ps1
@@ -8,7 +8,7 @@ param (
 
 function ConvertTo-Array([string] $rawInput)
 {
-    $rawInput.Replace("`r", "").Split("`n") | % { $_.Trim() } | ? { $_ }
+    $rawInput.Replace("`r", "").Split("`n") | ForEach-Object { $_.Trim() } | Where-Object { $_ }
 }
 
 Write-Output ".NET version number: $Version"
@@ -33,7 +33,7 @@ $buildSwitches = ConvertTo-Array @"
     $Switches
 "@
 
-[array] $expectedErrorCodes = ConvertTo-Array $ExpectedCodeAnalysisErrors | % { $_.Split(':')[0] } | Sort-Object
+[array] $expectedErrorCodes = ConvertTo-Array $ExpectedCodeAnalysisErrors | ForEach-Object { $_.Split(':')[0] } | Sort-Object
 $noErrors = $expectedErrorCodes.Count -eq 0
 
 if (Test-Path src/Utilities/Lombiq.Gulp.Extensions/Lombiq.Gulp.Extensions.csproj)
@@ -59,7 +59,7 @@ $errorLines = New-Object "System.Collections.Generic.List[string]"
 $errorCodes = New-Object "System.Collections.Generic.List[string]"
 
 $errorFormat = '^(.*)\((\d+),(\d+)\): error (.*)'
-dotnet build $SolutionOrProject @buildSwitches 2>&1 | % {
+dotnet build $SolutionOrProject @buildSwitches 2>&1 | ForEach-Object {
     if ($_ -notmatch $errorFormat) { return $_ }
 
     ($null, $file, $line, $column, $message) = [regex]::Match($_, $errorFormat, 'Compiled').Groups.Value
diff --git a/.github/actions/build-dotnet/Write-CacheConfiguration.ps1 b/.github/actions/build-dotnet/Write-CacheConfiguration.ps1
index f49361e42..888671420 100644
--- a/.github/actions/build-dotnet/Write-CacheConfiguration.ps1
+++ b/.github/actions/build-dotnet/Write-CacheConfiguration.ps1
@@ -9,12 +9,12 @@ if ($IsNuget) { $paths += ,'~/.nuget/packages' }
 if ($IsNpm)
 {
     (Invoke-Maybe { pnpm store path }), (npm config get cache) |
-        ? { -not [string]::IsNullOrEmpty($_) } |
-        % { $paths += $_ }
+        Where-Object { -not [string]::IsNullOrEmpty($_) } |
+        ForEach-Object { $paths += $_ }
 }
 
 # Ensure the paths exist.
-$paths | % { New-Item -ItemType Directory -Force $_ } | Out-Null
+$paths | ForEach-Object { New-Item -ItemType Directory -Force $_ } | Out-Null
 
 # Multiple paths must be separated by "\n", but we can't include newline in the workflow command so we have to misuse
 # the format function like this.
diff --git a/.github/actions/cancel-workflow/action.yml b/.github/actions/cancel-workflow/action.yml
index 880634a2a..e85419d97 100644
--- a/.github/actions/cancel-workflow/action.yml
+++ b/.github/actions/cancel-workflow/action.yml
@@ -1,7 +1,13 @@
 name: Cancel Workflow
 description: >
   Cancels the current workflow run, i.e. all jobs. Useful if you want to cancel the rest of the workflow when one job
-  fails.
+  fails. Note that this will cause the workflow to appear cancelled, not failed.
+
+# Cancelling the workflow in a post-script (like this:
+# https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#runspost; can also be done with
+# this action: https://github.com/webiny/action-post-run, see Git history of this file) wouldn't help the status, it
+# would still be cancelled. It actually indeed is, but it would be nicer to set it to failed, but there seems to be no
+# way to do this.
 
 runs:
   using: "composite"
@@ -11,6 +17,7 @@ runs:
       if: github.event.pull_request == '' || github.event.pull_request.head.repo.fork == false
       shell: pwsh
       run: |
+        Write-Output "::error::Canceling workflow due to one of the jobs failing."
         $url = "https://api.github.com/repos/${{ github.repository }}/actions/runs/${{ github.run_id }}/cancel"
         $headers = @{"Authorization" = "Bearer ${{ env.GITHUB_TOKEN }}"; "Accept" = "application/vnd.github+json"}
         Invoke-WebRequest $url -Headers $headers -Method Post
diff --git a/.github/actions/test-dotnet/Invoke-SolutionTests.ps1 b/.github/actions/test-dotnet/Invoke-SolutionTests.ps1
index f4cc0a983..006415e1c 100644
--- a/.github/actions/test-dotnet/Invoke-SolutionTests.ps1
+++ b/.github/actions/test-dotnet/Invoke-SolutionTests.ps1
@@ -31,39 +31,47 @@ $tests = dotnet sln list |
     Select-String "\.Tests\." |
     Select-String -NotMatch "Lombiq.Tests.UI.csproj" |
     Select-String -NotMatch "Lombiq.Tests.csproj" |
-    ? {
+    Where-Object {
         $result = dotnet test --no-restore --list-tests --verbosity $Verbosity $_ 2>&1 | Out-String -Width 9999
         -not [string]::IsNullOrEmpty($result) -and $result.Contains("The following Tests are available")
     }
 
+Write-Output "Starting to execute tests from $($tests.Length) projects."
+
 foreach ($test in $tests) {
+    # This could benefit from grouping, above the level of the potential groups created by the tests (the Lombiq UI
+    # Testing Toolbox adds per-test groups too). However, there's no nested grouping, see
+    # https://github.com/actions/runner/issues/1477. See the # c341ef145d2a0898c5900f64604b67b21d2ea5db commit for a
+    # nested grouping implementation.
+
+    Write-Output "Starting to execute tests from the $test project."
+
     $dotnetTestSwitches = @(
         '--configuration', 'Release'
         '--no-restore',
         '--no-build',
         '--nologo',
         '--logger', 'trx;LogFileName=test-results.trx'
+        # This is for xUnit ITestOutputHelper, see https://xunit.net/docs/capturing-output.
+        '--logger', 'console;verbosity=detailed'
         '--verbosity', $Verbosity
         $Filter ? '--filter' : ''
         $Filter ? $Filter : ''
         $test
     )
 
-    dotnet test @dotnetTestSwitches 2>&1 >test.out
+    # Filtering is necessary for annoying messages coming from UI testing but only under Ubuntu. There are no actual
+    # errors.
+    dotnet test @dotnetTestSwitches 2>&1 |
+        Where-Object { $_ -notlike '*Connection refused [[]::ffff:127.0.0.1[]]*' -and $_ -notlike '*ChromeDriver was started successfully*' }
 
     if ($?)
     {
-        Write-Output "Test Successful: $test"
+        Write-Output "Test successful: $test"
         continue
     }
 
-    $needsGrouping = (Select-String "::group::" test.out).Length -eq 0
-
-    if ($needsGrouping) { Write-Output "::group::Test Failed: $test" }
-
-    bash -c "cat test.out | grep -v 'Connection refused \[::ffff:127.0.0.1\]' | grep -v 'ChromeDriver was started successfully'"
-
-    if ($needsGrouping) { Write-Output "::endgroup::" }
+    Write-Output "Test failed: $test"
 
     exit 100
 }
diff --git a/.github/actions/test-dotnet/Merge-FailureDumps.ps1 b/.github/actions/test-dotnet/Merge-FailureDumps.ps1
index 92618aab6..b6d3acdea 100644
--- a/.github/actions/test-dotnet/Merge-FailureDumps.ps1
+++ b/.github/actions/test-dotnet/Merge-FailureDumps.ps1
@@ -6,6 +6,6 @@ $testDirectory = "$Directory/test"
 $rootDirectory = (Test-Path -Path $testDirectory) ? $testDirectory : $Directory
 
 Get-ChildItem $rootDirectory -Recurse |
-    ? { $_.Name -eq 'FailureDumps' } |
-    % { $_.GetDirectories() } |
-    % { Move-Item $_.FullName "$Directory/FailureDumps/${_.Name}" }
+    Where-Object { $_.Name -eq 'FailureDumps' } |
+    ForEach-Object { $_.GetDirectories() } |
+    ForEach-Object { Move-Item $_.FullName "$Directory/FailureDumps/${_.Name}" }
diff --git a/.github/actions/test-dotnet/action.yml b/.github/actions/test-dotnet/action.yml
index c2010060c..00c645f02 100644
--- a/.github/actions/test-dotnet/action.yml
+++ b/.github/actions/test-dotnet/action.yml
@@ -73,9 +73,7 @@ runs:
       if: success() || failure()
       with:
         name: ui-test-failure-dump-${{ steps.setup.outputs.friendly-build-directory-name }}-${{ steps.setup.outputs.runner-suffix }}
-        path: |
-          ${{ inputs.build-directory }}/FailureDumps/
-          test.out
+        path: ${{ inputs.build-directory }}/FailureDumps/
         if-no-files-found: ignore
 
     - name: Test Report
diff --git a/.github/actions/verify-submodule-pull-request/Check-Parent.ps1 b/.github/actions/verify-submodule-pull-request/Check-Parent.ps1
index 9a301938b..97874d100 100644
--- a/.github/actions/verify-submodule-pull-request/Check-Parent.ps1
+++ b/.github/actions/verify-submodule-pull-request/Check-Parent.ps1
@@ -4,7 +4,7 @@ param(
 )
 
 $url = "https://api.github.com/repos/$Repository/pulls?state=open&per_page=100"
-$titles = curl -s -H 'Accept: application/vnd.github.v3+json' $url | ConvertFrom-Json | % { $_.title }
+$titles = curl -s -H 'Accept: application/vnd.github.v3+json' $url | ConvertFrom-Json | ForEach-Object { $_.title }
 
 $issueCode = $Title -replace '^\s*(\w+-\d+)\s*:.*$', '$1'
 $lookFor = "${issueCode}:"