diff --git a/azure-pipelines/e2e-ports/ci-independent-regression/v1/regression/portfile.cmake b/azure-pipelines/e2e-ports/ci-independent-regression/v1/regression/portfile.cmake
new file mode 100644
index 0000000000..065116c276
--- /dev/null
+++ b/azure-pipelines/e2e-ports/ci-independent-regression/v1/regression/portfile.cmake
@@ -0,0 +1 @@
+set(VCPKG_POLICY_EMPTY_PACKAGE enabled)
diff --git a/azure-pipelines/e2e-ports/ci-independent-regression/v1/regression/vcpkg.json b/azure-pipelines/e2e-ports/ci-independent-regression/v1/regression/vcpkg.json
new file mode 100644
index 0000000000..ea1039fb59
--- /dev/null
+++ b/azure-pipelines/e2e-ports/ci-independent-regression/v1/regression/vcpkg.json
@@ -0,0 +1,12 @@
+{
+  "name": "regression",
+  "version": "1",
+  "dependencies": [
+    {
+      "name": "feature-fails",
+      "features": [
+        "fail"
+      ]
+    }
+  ]
+}
diff --git a/azure-pipelines/e2e-ports/ci-independent-regression/v2/regression/portfile.cmake b/azure-pipelines/e2e-ports/ci-independent-regression/v2/regression/portfile.cmake
new file mode 100644
index 0000000000..065116c276
--- /dev/null
+++ b/azure-pipelines/e2e-ports/ci-independent-regression/v2/regression/portfile.cmake
@@ -0,0 +1 @@
+set(VCPKG_POLICY_EMPTY_PACKAGE enabled)
diff --git a/azure-pipelines/e2e-ports/ci-independent-regression/v2/regression/vcpkg.json b/azure-pipelines/e2e-ports/ci-independent-regression/v2/regression/vcpkg.json
new file mode 100644
index 0000000000..33341a58eb
--- /dev/null
+++ b/azure-pipelines/e2e-ports/ci-independent-regression/v2/regression/vcpkg.json
@@ -0,0 +1,12 @@
+{
+  "name": "regression",
+  "version": "2",
+  "dependencies": [
+    {
+      "name": "feature-fails",
+      "features": [
+        "fail"
+      ]
+    }
+  ]
+}
diff --git a/azure-pipelines/e2e-ports/ci/feature-fails/portfile.cmake b/azure-pipelines/e2e-ports/ci/feature-fails/portfile.cmake
new file mode 100644
index 0000000000..e24b12f61b
--- /dev/null
+++ b/azure-pipelines/e2e-ports/ci/feature-fails/portfile.cmake
@@ -0,0 +1,4 @@
+set(VCPKG_POLICY_EMPTY_PACKAGE enabled)
+if("fail" IN_LIST FEATURES)
+    message(FATAL_ERROR "Failing, triggered by feature 'fail'.")
+endif()
diff --git a/azure-pipelines/e2e-ports/ci/feature-fails/vcpkg.json b/azure-pipelines/e2e-ports/ci/feature-fails/vcpkg.json
new file mode 100644
index 0000000000..1714f8cc76
--- /dev/null
+++ b/azure-pipelines/e2e-ports/ci/feature-fails/vcpkg.json
@@ -0,0 +1,9 @@
+{
+  "name": "feature-fails",
+  "version": "1",
+  "features": {
+    "fail": {
+      "description": "fails to build"
+    }
+  }
+}
diff --git a/azure-pipelines/end-to-end-tests-dir/ci.ps1 b/azure-pipelines/end-to-end-tests-dir/ci.ps1
index 87ffc1a8df..bd86a95fa3 100644
--- a/azure-pipelines/end-to-end-tests-dir/ci.ps1
+++ b/azure-pipelines/end-to-end-tests-dir/ci.ps1
@@ -17,8 +17,8 @@ if (-not ($Output.Contains("feature-not-sup:${Triplet}:        *"))) {
 if (-not ($Output.Contains("feature-dep-missing:${Triplet}:        *"))) {
     throw 'feature-dep-missing must be built because the broken feature is not selected.'
 }
-if ($Output.Split("*").Length -ne 4) {
-    throw 'base-port should not be installed for the host'
+if ($Output.Split("*: ").Length -ne 5) {
+    throw 'Exactly 4 ports should be installed'
 }
 if (-not ($ErrorOutput.Contains("REGRESSION: not-sup-host-b:${Triplet} is marked as fail but not supported for ${Triplet}."))) {
     throw "feature-not-sup's baseline fail entry should result in a regression because the port is not supported"
@@ -80,6 +80,9 @@ Throw-IfFailed
 if (-not ($Output.Contains("base-port:${Triplet}: SUCCEEDED:"))) {
     throw 'base-port build must succeed'
 }
+if (-not ($Output.Contains("feature-fails:${Triplet}: SUCCEEDED:"))) {
+    throw 'feature-fails[core] build must succeed'
+}
 Remove-Item -Recurse -Force $installRoot -ErrorAction SilentlyContinue
 New-Item -ItemType Directory -Path $installRoot -Force | Out-Null
 $Output = Run-VcpkgAndCaptureOutput ci @commonArgs --x-builtin-ports-root="$PSScriptRoot/../e2e-ports/ci" --binarysource="clear;files,$ArchiveRoot" --parent-hashes="$TestingRoot/parent-hashes.json"
@@ -87,3 +90,35 @@ Throw-IfFailed
 if ($Output.Contains("base-port:${Triplet}: SUCCEEDED:")) {
     throw 'base-port must not be rebuilt again'
 }
+
+# With parent-hashes, test detection of regressions of independent ports.
+Remove-Item -Recurse -Force $installRoot -ErrorAction SilentlyContinue
+New-Item -ItemType Directory -Path $installRoot -Force | Out-Null
+Remove-Item -Recurse -Force $ArchiveRoot -ErrorAction SilentlyContinue
+New-Item -ItemType Directory -Path $ArchiveRoot -Force | Out-Null
+# A dry run in order to determine all parent hashes without failing, regression@1
+$Output = Run-VcpkgAndCaptureOutput ci --dry-run @commonArgs --x-builtin-ports-root="$PSScriptRoot/../e2e-ports/ci"  --binarysource="clear;files,$ArchiveRoot" --output-hashes="$TestingRoot/parent-hashes.json"  --overlay-ports="$PSScriptRoot/../e2e-ports/ci-independent-regression/v1"
+Throw-IfFailed
+Remove-Item -Recurse -Force $installRoot -ErrorAction SilentlyContinue
+New-Item -ItemType Directory -Path $installRoot -Force | Out-Null
+# Non-dry run with port regression@2
+$Output = Run-VcpkgAndCaptureOutput ci @commonArgs --x-builtin-ports-root="$PSScriptRoot/../e2e-ports/ci" --binarysource="clear;files,$ArchiveRoot" --parent-hashes="$TestingRoot/parent-hashes.json"  --overlay-ports="$PSScriptRoot/../e2e-ports/ci-independent-regression/v2"
+Throw-IfNotFailed
+if ($Output.Contains("base-port:${Triplet}: SUCCEEDED:")) {
+    throw 'base-port must not be rebuilt again'
+}
+if (-not ($Output.Contains("feature-fails:${Triplet}: BUILD_FAILED:"))) {
+    throw 'feature-fails[fail] build must fail'
+}
+if (-not ($Output.Contains("regression:${Triplet}: CASCADED_DUE_TO_MISSING_DEPENDENCIES:"))) {
+    throw 'regression build must cascade'
+}
+# Non-dry run with port regression@2
+$Output = Run-VcpkgAndCaptureStdErr ci @commonArgs --x-builtin-ports-root="$PSScriptRoot/../e2e-ports/ci" --binarysource="clear;files,$ArchiveRoot" --parent-hashes="$TestingRoot/parent-hashes.json"  --overlay-ports="$PSScriptRoot/../e2e-ports/ci-independent-regression/v2"
+Throw-IfNotFailed
+if (-not ($Output.Contains("REGRESSION: Independent feature-fails:${Triplet} failed with BUILD_FAILED."))) {
+    throw 'feature-fails[fail] build failure must be reported as independent regression'
+}
+if ($Output.Contains("REGRESSION: Independent regression:${Triplet} failed with BUILD_FAILED.")) {
+    throw 'regression (port) build failure must not be reported as independent regression'
+}
diff --git a/src/vcpkg/commands.ci.cpp b/src/vcpkg/commands.ci.cpp
index c97635636b..722ab29cdc 100644
--- a/src/vcpkg/commands.ci.cpp
+++ b/src/vcpkg/commands.ci.cpp
@@ -173,6 +173,8 @@ namespace
                             const std::map<PackageSpec, BuildResult>& known,
                             View<std::string> parent_hashes)
     {
+        // With parent hashes, ports are merely "auto selected" unless the abi hash changed.
+        auto const default_request_type = parent_hashes.empty() ? RequestType::USER_REQUESTED : RequestType::AUTO_SELECTED;
         std::set<PackageSpec> to_keep;
         for (auto it = action_plan.install_actions.rbegin(); it != action_plan.install_actions.rend(); ++it)
         {
@@ -187,6 +189,10 @@ namespace
                     to_keep.insert(it->spec);
                 }
             }
+            else
+            {
+                it->request_type = default_request_type;
+            }
 
             if (Util::Sets::contains(to_keep, it->spec))
             {