diff --git a/.github/workflows/benchmarks.yml b/.github/workflows/benchmarks.yml
index 19bc0391a0..31605140f0 100644
--- a/.github/workflows/benchmarks.yml
+++ b/.github/workflows/benchmarks.yml
@@ -68,6 +68,11 @@ on:
         description: "Boolean to enable the Windows nightly main Swift version matrix job. Currently has no effect!"  # TODO: implement Windows benchmarking
         default: false
 
+      linux_env_vars:
+        type: string
+        description: "Environment variables for Linux jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+
 jobs:
   construct-matrix:
     name: Construct Benchmarks matrix
@@ -80,7 +85,16 @@ jobs:
         with:
           persist-credentials: false
       - id: generate-matrix
-        run: echo "benchmarks-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | bash)" >> "$GITHUB_OUTPUT"
+        run: |
+          # Validate JSON environment variables
+          linux_env_vars_json='${{ inputs.linux_env_vars }}'
+
+          if ! echo "$linux_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: linux_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          echo "benchmarks-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | MATRIX_LINUX_ENV_VARS_JSON="${linux_env_vars_json}" bash)" >> "$GITHUB_OUTPUT"
         env:
           MATRIX_LINUX_COMMAND: "curl -s https://raw.githubusercontent.com/apple/swift-nio/main/scripts/check_benchmark_thresholds.sh | BENCHMARK_PACKAGE_PATH=${{ inputs.benchmark_package_path }} bash"
           MATRIX_LINUX_SETUP_COMMAND: "swift --version && apt-get update -y -q && apt-get install -y -q curl libjemalloc-dev && git config --global --add safe.directory /$(basename ${{ github.workspace }})"
diff --git a/.github/workflows/cxx_interop.yml b/.github/workflows/cxx_interop.yml
index 480df6c958..5076619e23 100644
--- a/.github/workflows/cxx_interop.yml
+++ b/.github/workflows/cxx_interop.yml
@@ -61,6 +61,15 @@ on:
         description: "Boolean to enable the Windows nightly main Swift version matrix job. Defaults to false. Currently has no effect!"  # TODO: implement Windows Cxx compat checking
         default: false
 
+      linux_env_vars:
+        type: string
+        description: "Environment variables for Linux jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+      windows_env_vars:
+        type: string
+        description: "Environment variables for Windows jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+
 jobs:
   construct-matrix:
     name: Construct Cxx interop matrix
@@ -73,7 +82,22 @@ jobs:
         with:
           persist-credentials: false
       - id: generate-matrix
-        run: echo "cxx-interop-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | bash)" >> "$GITHUB_OUTPUT"
+        run: |
+          # Validate JSON environment variables
+          linux_env_vars_json='${{ inputs.linux_env_vars }}'
+          windows_env_vars_json='${{ inputs.windows_env_vars }}'
+
+          if ! echo "$linux_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: linux_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          if ! echo "$windows_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: windows_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          echo "cxx-interop-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | MATRIX_LINUX_ENV_VARS_JSON="${linux_env_vars_json}" MATRIX_WINDOWS_ENV_VARS_JSON="${windows_env_vars_json}" bash)" >> "$GITHUB_OUTPUT"
         env:
           MATRIX_LINUX_COMMAND: "curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/check-cxx-interop-compatibility.sh | bash"
           MATRIX_LINUX_SETUP_COMMAND: "swift --version && apt-get update -y -q && apt-get install -y -q curl jq"
diff --git a/.github/workflows/macos_tests.yml b/.github/workflows/macos_tests.yml
index 482a0f4b12..73f8b6c769 100644
--- a/.github/workflows/macos_tests.yml
+++ b/.github/workflows/macos_tests.yml
@@ -193,6 +193,11 @@ on:
         description: "The runner pool which will be requested."
         default: "nightly"
 
+      env_vars:
+        type: string
+        description: "Environment variables for jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+
 jobs:
   construct-matrix:
     name: Construct Darwin matrix
@@ -206,6 +211,15 @@ jobs:
           persist-credentials: false
       - id: generate-matrix
         run: |
+          # Validate and use JSON environment variables directly
+          env_vars_json='${{ inputs.env_vars }}'
+
+          # Validate JSON format
+          if ! echo "$env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: env_vars is not valid JSON"
+            exit 1
+          fi
+
           cat >> "$GITHUB_OUTPUT" << EOM
           darwin-matrix=$(
             runner_pool="${MATRIX_RUNNER_POOL:="nightly"}"
@@ -255,7 +269,8 @@ jobs:
                 --arg build_arguments_override "$xcode_15_4_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_15_4_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 15.4", "xcode_version": "15.4", "xcode_app": "Xcode_15.4.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 15.4", "xcode_version": "15.4", "xcode_app": "Xcode_15.4.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_16_0_enabled" == "true" ]]; then
@@ -264,7 +279,8 @@ jobs:
                 --arg build_arguments_override "$xcode_16_0_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_16_0_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 16.0", "xcode_version": "16.0", "xcode_app": "Xcode_16.0.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 16.0", "xcode_version": "16.0", "xcode_app": "Xcode_16.0.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_16_1_enabled" == "true" ]]; then
@@ -273,7 +289,8 @@ jobs:
                 --arg build_arguments_override "$xcode_16_1_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_16_1_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 16.1", "xcode_version": "16.1", "xcode_app": "Xcode_16.1.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 16.1", "xcode_version": "16.1", "xcode_app": "Xcode_16.1.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_16_2_enabled" == "true" ]]; then
@@ -282,7 +299,8 @@ jobs:
                 --arg build_arguments_override "$xcode_16_2_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_16_2_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 16.2", "xcode_version": "16.2", "xcode_app": "Xcode_16.2.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 16.2", "xcode_version": "16.2", "xcode_app": "Xcode_16.2.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_16_3_enabled" == "true" ]]; then
@@ -291,7 +309,8 @@ jobs:
                 --arg build_arguments_override "$xcode_16_3_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_16_3_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 16.3", "xcode_version": "16.3", "xcode_app": "Xcode_16.3.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 16.3", "xcode_version": "16.3", "xcode_app": "Xcode_16.3.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_16_4_enabled" == "true" ]]; then
@@ -300,7 +319,8 @@ jobs:
                 --arg build_arguments_override "$xcode_16_4_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_16_4_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 16.4", "xcode_version": "16.4", "xcode_app": "Xcode_16.4.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 16.4", "xcode_version": "16.4", "xcode_app": "Xcode_16.4.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_26_0_enabled" == "true" ]]; then
@@ -309,7 +329,8 @@ jobs:
                 --arg build_arguments_override "$xcode_26_0_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_26_0_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode 26.0", "xcode_version": "26.0", "xcode_app": "Xcode_26.0.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode 26.0", "xcode_version": "26.0", "xcode_app": "Xcode_26.0.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             if [[ "$xcode_latest_beta_enabled" == "true" ]]; then
@@ -318,7 +339,8 @@ jobs:
                 --arg build_arguments_override "$xcode_latest_beta_build_arguments_override"  \
                 --arg test_arguments_override "$xcode_latest_beta_test_arguments_override"  \
                 --arg runner_pool "$runner_pool"  \
-                '.config[.config| length] |= . + { "name": "Xcode latest beta", "xcode_version": "latest beta", "xcode_app": "Xcode-latest.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool }')
+                --argjson env_vars "$env_vars_json" \
+                '.config[.config| length] |= . + { "name": "Xcode latest beta", "xcode_version": "latest beta", "xcode_app": "Xcode-latest.app", "setup_command": $setup_command, "build_arguments_override": $build_arguments_override, "test_arguments_override": $test_arguments_override, "os": "sequoia", "arch": "ARM64", "pool": $runner_pool, "env": $env_vars }')
             fi
 
             echo "$matrix" | jq -c
@@ -377,6 +399,12 @@ jobs:
         with:
           persist-credentials: false
           submodules: true
+      - name: Export environment variables
+        if: ${{ matrix.config.env != '' && matrix.config.env != '{}'}}
+        run: |
+          echo "Exporting environment variables from matrix configuration..."
+          echo '${{ toJSON(matrix.config.env) }}' | jq -r 'to_entries[] | "\(.key)=\(.value)"' >> $GITHUB_ENV
+          echo '${{ toJSON(matrix.config.env) }}' | jq -r 'to_entries[] | "exporting \(.key)=\(.value)"'
       - name: Setup command
         if: ${{ matrix.config.setup_command != '' }}
         run: bash -c "${{ matrix.config.setup_command }}"
diff --git a/.github/workflows/release_builds.yml b/.github/workflows/release_builds.yml
index 01079a8b32..6c605b5679 100644
--- a/.github/workflows/release_builds.yml
+++ b/.github/workflows/release_builds.yml
@@ -93,6 +93,15 @@ on:
         description: "The arguments passed to swift test in the Windows nightly main Swift version matrix job."
         default: ""
 
+      linux_env_vars:
+        type: string
+        description: "Environment variables for Linux jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+      windows_env_vars:
+        type: string
+        description: "Environment variables for Windows jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+
 jobs:
   construct-matrix:
     name: Construct release build matrix
@@ -105,7 +114,22 @@ jobs:
         with:
           persist-credentials: false
       - id: generate-matrix
-        run: echo "release-build-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | bash)" >> "$GITHUB_OUTPUT"
+        run: |
+          # Validate JSON environment variables
+          linux_env_vars_json='${{ inputs.linux_env_vars }}'
+          windows_env_vars_json='${{ inputs.windows_env_vars }}'
+
+          if ! echo "$linux_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: linux_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          if ! echo "$windows_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: windows_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          echo "release-build-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | MATRIX_LINUX_ENV_VARS_JSON="${linux_env_vars_json}" MATRIX_WINDOWS_ENV_VARS_JSON="${windows_env_vars_json}" bash)" >> "$GITHUB_OUTPUT"
         env:
           MATRIX_LINUX_SETUP_COMMAND: "swift --version"
           MATRIX_LINUX_COMMAND: "swift build -c release"
diff --git a/.github/workflows/static_sdk.yml b/.github/workflows/static_sdk.yml
index b00477abe9..cae0205f22 100644
--- a/.github/workflows/static_sdk.yml
+++ b/.github/workflows/static_sdk.yml
@@ -2,36 +2,69 @@ name: Static SDK
 
 on:
   workflow_call:
+    inputs:
+      env_vars:
+        type: string
+        description: "Environment variables for jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
 
 jobs:
+  construct-matrix:
+    name: Construct Static SDK matrix
+    runs-on: ubuntu-latest
+    outputs:
+      static-sdk-matrix: '${{ steps.generate-matrix.outputs.static-sdk-matrix }}'
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - id: generate-matrix
+        run: |
+          # Validate and use JSON environment variables directly
+          env_vars_json='${{ inputs.env_vars }}'
+
+          # Validate JSON format
+          if ! echo "$env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: env_vars is not valid JSON"
+            exit 1
+          fi
+
+          # Generate matrix with parsed environment variables
+          cat >> "$GITHUB_OUTPUT" << EOM
+          static-sdk-matrix=$(echo '{
+            "config":[
+              {
+                "name":"latest-release Jammy",
+                "swift_version":"latest-release",
+                "platform":"Linux",
+                "runner":"ubuntu-latest",
+                "image":"ubuntu:jammy",
+                "setup_command":"apt update -q && apt install -y -q curl jq tar && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_swift_prerequisites.sh | bash && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_static_sdk.sh | INSTALL_SWIFT_STATIC_SDK_VERSION=latest INSTALL_SWIFT_STATIC_SDK_ARCH=x86_64 bash && hash -r",
+                "command":"swift build",
+                "command_arguments":"--swift-sdk x86_64-swift-linux-musl",
+                "env":'"$env_vars_json"'
+              },
+              {
+                "name":"main Jammy",
+                "swift_version":"main",
+                "platform":"Linux",
+                "runner":"ubuntu-latest",
+                "image":"ubuntu:jammy",
+                "setup_command":"apt update -q && apt install -y -q curl jq tar && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_swift_prerequisites.sh | bash && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_static_sdk.sh | INSTALL_SWIFT_STATIC_SDK_BRANCH=main INSTALL_SWIFT_STATIC_SDK_ARCH=x86_64 bash && hash -r",
+                "command":"swift build",
+                "command_arguments":"--swift-sdk x86_64-swift-linux-musl",
+                "env":'"$env_vars_json"'
+              }
+            ]
+          }' | jq -c)
+          EOM
+
   static-sdk:
     name: Static SDK
+    needs: construct-matrix
     # Workaround https://github.com/nektos/act/issues/1875
     uses: apple/swift-nio/.github/workflows/swift_test_matrix.yml@main
     with:
       name: "Static SDK"
-      matrix_string: >-
-        {
-          "config":[
-            {
-              "name":"latest-release Jammy",
-              "swift_version":"latest-release",
-              "platform":"Linux",
-              "runner":"ubuntu-latest",
-              "image":"ubuntu:jammy",
-              "setup_command":"apt update -q && apt install -y -q curl jq tar && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_swift_prerequisites.sh | bash && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_static_sdk.sh | INSTALL_SWIFT_STATIC_SDK_VERSION=latest INSTALL_SWIFT_STATIC_SDK_ARCH=x86_64 bash && hash -r",
-              "command":"swift build",
-              "command_arguments":"--swift-sdk x86_64-swift-linux-musl"
-            },
-            {
-              "name":"main Jammy",
-              "swift_version":"main",
-              "platform":"Linux",
-              "runner":"ubuntu-latest",
-              "image":"ubuntu:jammy",
-              "setup_command":"apt update -q && apt install -y -q curl jq tar && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_swift_prerequisites.sh | bash && curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/install_static_sdk.sh | INSTALL_SWIFT_STATIC_SDK_BRANCH=main INSTALL_SWIFT_STATIC_SDK_ARCH=x86_64 bash && hash -r",
-              "command":"swift build",
-              "command_arguments":"--swift-sdk x86_64-swift-linux-musl"
-            }
-          ]
-        }
+      matrix_string: '${{ needs.construct-matrix.outputs.static-sdk-matrix }}'
diff --git a/.github/workflows/swift_test_matrix.yml b/.github/workflows/swift_test_matrix.yml
index 4d0a12bff9..69f623e49a 100644
--- a/.github/workflows/swift_test_matrix.yml
+++ b/.github/workflows/swift_test_matrix.yml
@@ -41,15 +41,30 @@ jobs:
             setup_command_expression=""
           fi
           workspace="/$(basename ${{ github.workspace }})"
-          docker run -v ${{ github.workspace }}:"$workspace" \
-            -w "$workspace" \
-            -e CI="$CI" \
-            -e GITHUB_ACTIONS="$GITHUB_ACTIONS" \
-            -e SWIFT_VERSION="${{ matrix.config.swift_version }}" \
-            -e setup_command_expression="$setup_command_expression" \
-            -e workspace="$workspace" \
-            ${{ matrix.config.image }} \
-            bash -c "$setup_command_expression ${{ matrix.config.command }} ${{ matrix.config.command_arguments }}"
+
+          docker_args=(
+            "run"
+            "-v" "${{ github.workspace }}:$workspace"
+            "-w" "$workspace"
+            "-e" "CI=$CI"
+            "-e" "GITHUB_ACTIONS=$GITHUB_ACTIONS"
+            "-e" "SWIFT_VERSION=${{ matrix.config.swift_version }}"
+            "-e" "workspace=$workspace"
+          )
+
+          if [[ '${{ toJson(matrix.config.env) }}' != '{}' ]]; then
+            while IFS="=" read -r key value; do
+              if [[ -n "$key" && -n "$value" ]]; then
+                docker_args+=("-e" "$key=$value")
+              fi
+            done < <(echo '${{ toJson(matrix.config.env) }}' | jq -r 'to_entries[] | "\(.key)=\(.value)"')
+          fi
+
+          docker_args+=("${{ matrix.config.image }}")
+          docker_args+=("bash" "-c" "$setup_command_expression ${{ matrix.config.command }} ${{ matrix.config.command_arguments }}")
+
+          echo "Executing Docker command: docker ${docker_args[*]}"
+          docker "${docker_args[@]}"
       - name: Run matrix job (Windows)
         if: ${{ matrix.config.platform == 'Windows' }}
         run: |
@@ -59,13 +74,29 @@ jobs:
               $setup_command_expression = ""
           }
           $workspace = "C:\" + (Split-Path ${{ github.workspace }} -Leaf)
-          docker run -v ${{ github.workspace }}:$($workspace) `
-            -w $($workspace) `
-            -e CI=%CI% `
-            -e GITHUB_ACTIONS=%GITHUB_ACTIONS% `
-            -e SWIFT_VERSION="${{ matrix.config.swift_version }}" `
-            -e setup_command_expression=%setup_command_expression% `
-            ${{ matrix.config.image }} `
-            cmd /s /c  "swift --version & $($setup_command_expression) ${{ matrix.config.command }} ${{ matrix.config.command_arguments }}"
+
+          $docker_args = @(
+              "run", "-v", "${{ github.workspace }}:$($workspace)",
+              "-w", $workspace,
+              "-e", "CI=$env:CI",
+              "-e", "GITHUB_ACTIONS=$env:GITHUB_ACTIONS",
+              "-e", "SWIFT_VERSION=${{ matrix.config.swift_version }}"
+          )
+
+          $env_args = @()
+          $env_json = '${{ toJson(matrix.config.env) }}'
+          if ($env_json -ne '{}') {
+              $env_obj = $env_json | ConvertFrom-Json
+              $env_obj.PSObject.Properties | ForEach-Object {
+                  $env_args += "-e"
+                  $env_args += "$($_.Name)=$($_.Value)"
+              }
+          }
+          $docker_args += $env_args
+
+          $docker_args += @("${{ matrix.config.image }}", "cmd", "/s", "/c", "swift --version & $($setup_command_expression) ${{ matrix.config.command }} ${{ matrix.config.command_arguments }}")
+
+          Write-Host "Executing Docker command: docker $($docker_args -join ' ')"
+          & docker @docker_args
     env:
       SWIFT_VERSION: ${{ matrix.config.swift_version }}
diff --git a/.github/workflows/unit_tests.yml b/.github/workflows/unit_tests.yml
index a94073307e..e9874b6e49 100644
--- a/.github/workflows/unit_tests.yml
+++ b/.github/workflows/unit_tests.yml
@@ -133,6 +133,15 @@ on:
         description: "The arguments passed to swift test in the Windows nightly main Swift version matrix job."
         default: ""
 
+      linux_env_vars:
+        type: string
+        description: "Environment variables for Linux jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+      windows_env_vars:
+        type: string
+        description: "Environment variables for Windows jobs as JSON (e.g., '{\"DEBUG\":\"1\",\"LOG_LEVEL\":\"info\"}')."
+        default: "{}"
+
 jobs:
   construct-matrix:
     name: Construct unit test matrix
@@ -145,7 +154,24 @@ jobs:
         with:
           persist-credentials: false
       - id: generate-matrix
-        run: echo "unit-test-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | bash)" >> "$GITHUB_OUTPUT"
+        run: |
+          # Validate and use JSON environment variables directly
+          linux_env_vars_json='${{ inputs.linux_env_vars }}'
+          windows_env_vars_json='${{ inputs.windows_env_vars }}'
+
+          # Validate JSON format
+          if ! echo "$linux_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: linux_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          if ! echo "$windows_env_vars_json" | jq empty 2>/dev/null; then
+            echo "Error: windows_env_vars is not valid JSON"
+            exit 1
+          fi
+
+          # Generate matrix
+          echo "unit-test-matrix=$(curl -s --retry 3 https://raw.githubusercontent.com/apple/swift-nio/main/scripts/generate_matrix.sh | MATRIX_LINUX_ENV_VARS_JSON="${linux_env_vars_json}" MATRIX_WINDOWS_ENV_VARS_JSON="${windows_env_vars_json}" bash)" >> "$GITHUB_OUTPUT"
         env:
           MATRIX_LINUX_SETUP_COMMAND: "swift --version"
           MATRIX_LINUX_COMMAND: "swift test"
diff --git a/scripts/generate_matrix.sh b/scripts/generate_matrix.sh
index 2ef13b5fe4..23fffd0f38 100755
--- a/scripts/generate_matrix.sh
+++ b/scripts/generate_matrix.sh
@@ -12,6 +12,7 @@
 ## SPDX-License-Identifier: Apache-2.0
 ##
 ##===----------------------------------------------------------------------===##
+set -x
 
 # Parameters
 linux_command="$MATRIX_LINUX_COMMAND"  # required if any Linux pipeline is enabled
@@ -65,6 +66,10 @@ windows_nightly_next_container_image="swiftlang/swift:nightly-6.2-windowsserverc
 windows_nightly_main_runner="windows-2022"
 windows_nightly_main_container_image="swiftlang/swift:nightly-main-windowsservercore-ltsc2022"
 
+# Get pre-parsed environment variables JSON
+linux_env_vars_json="${MATRIX_LINUX_ENV_VARS_JSON:-"{}"}"
+windows_env_vars_json="${MATRIX_WINDOWS_ENV_VARS_JSON:-"{}"}"
+
 # Create matrix from inputs
 matrix='{"config": []}'
 
@@ -91,7 +96,8 @@ if [[ "$linux_5_9_enabled" == "true" ]]; then
     --arg command_arguments "$linux_5_9_command_arguments" \
     --arg container_image "$linux_5_9_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "5.9", "image": $container_image, "swift_version": "5.9", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "5.9", "image": $container_image, "swift_version": "5.9", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 if [[ "$linux_5_10_enabled" == "true" ]]; then
@@ -101,7 +107,8 @@ if [[ "$linux_5_10_enabled" == "true" ]]; then
     --arg command_arguments "$linux_5_10_command_arguments" \
     --arg container_image "$linux_5_10_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "5.10", "image": $container_image, "swift_version": "5.10", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "5.10", "image": $container_image, "swift_version": "5.10", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 if [[ "$linux_6_0_enabled" == "true" ]]; then
@@ -111,7 +118,8 @@ if [[ "$linux_6_0_enabled" == "true" ]]; then
     --arg command_arguments "$linux_6_0_command_arguments" \
     --arg container_image "$linux_6_0_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "6.0", "image": $container_image, "swift_version": "6.0", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "6.0", "image": $container_image, "swift_version": "6.0", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 if [[ "$linux_6_1_enabled" == "true" ]]; then
@@ -121,7 +129,8 @@ if [[ "$linux_6_1_enabled" == "true" ]]; then
     --arg command_arguments "$linux_6_1_command_arguments" \
     --arg container_image "$linux_6_1_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "6.1", "image": $container_image, "swift_version": "6.1", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "6.1", "image": $container_image, "swift_version": "6.1", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 if [[ "$linux_6_2_enabled" == "true" ]]; then
@@ -131,7 +140,8 @@ if [[ "$linux_6_2_enabled" == "true" ]]; then
     --arg command_arguments "$linux_6_2_command_arguments" \
     --arg container_image "$linux_6_2_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "6.2", "image": $container_image, "swift_version": "6.2", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "6.2", "image": $container_image, "swift_version": "6.2", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 if [[ "$linux_nightly_next_enabled" == "true" ]]; then
@@ -141,7 +151,8 @@ if [[ "$linux_nightly_next_enabled" == "true" ]]; then
     --arg command_arguments "$linux_nightly_next_command_arguments" \
     --arg container_image "$linux_nightly_next_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "nightly-next", "image": $container_image, "swift_version": "nightly-next", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "nightly-next", "image": $container_image, "swift_version": "nightly-next", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 if [[ "$linux_nightly_main_enabled" == "true" ]]; then
@@ -151,12 +162,14 @@ if [[ "$linux_nightly_main_enabled" == "true" ]]; then
     --arg command_arguments "$linux_nightly_main_command_arguments" \
     --arg container_image "$linux_nightly_main_container_image" \
     --arg runner "$linux_runner" \
-    '.config[.config| length] |= . + { "name": "nightly-main", "image": $container_image, "swift_version": "nightly-main", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner}')
+    --argjson env_vars "$linux_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "nightly-main", "image": $container_image, "swift_version": "nightly-main", "platform": "Linux", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars}')
 fi
 
 ## Windows
 if [[ \
   "$windows_6_0_enabled" == "true" || \
+  "$windows_6_1_enabled" == "true" || \
   "$windows_nightly_next_enabled" == "true" || \
   "$windows_nightly_main_enabled" == "true" \
 ]]; then
@@ -172,7 +185,8 @@ if [[ "$windows_6_0_enabled" == "true" ]]; then
     --arg command_arguments "$windows_6_0_command_arguments" \
     --arg container_image "$windows_6_0_container_image" \
     --arg runner "$windows_6_0_runner" \
-    '.config[.config| length] |= . + { "name": "6.0", "image": $container_image, "swift_version": "6.0", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner }')
+    --argjson env_vars "$windows_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "6.0", "image": $container_image, "swift_version": "6.0", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars }')
 fi
 
 if [[ "$windows_6_1_enabled" == "true" ]]; then
@@ -182,7 +196,8 @@ if [[ "$windows_6_1_enabled" == "true" ]]; then
     --arg command_arguments "$windows_6_1_command_arguments" \
     --arg container_image "$windows_6_1_container_image" \
     --arg runner "$windows_6_1_runner" \
-    '.config[.config| length] |= . + { "name": "6.1", "image": $container_image, "swift_version": "6.1", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner }')
+    --argjson env_vars "$windows_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "6.1", "image": $container_image, "swift_version": "6.1", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars }')
 fi
 
 if [[ "$windows_6_2_enabled" == "true" ]]; then
@@ -192,7 +207,8 @@ if [[ "$windows_6_2_enabled" == "true" ]]; then
     --arg command_arguments "$windows_6_2_command_arguments" \
     --arg container_image "$windows_6_2_container_image" \
     --arg runner "$windows_6_2_runner" \
-    '.config[.config| length] |= . + { "name": "6.2", "image": $container_image, "swift_version": "6.2", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner }')
+    --argjson env_vars "$windows_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "6.2", "image": $container_image, "swift_version": "6.2", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars }')
 fi
 
 if [[ "$windows_nightly_next_enabled" == "true" ]]; then
@@ -202,7 +218,8 @@ if [[ "$windows_nightly_next_enabled" == "true" ]]; then
     --arg command_arguments "$windows_nightly_next_command_arguments" \
     --arg container_image "$windows_nightly_next_container_image" \
     --arg runner "$windows_nightly_next_runner" \
-    '.config[.config| length] |= . + { "name": "nightly-next", "image": $container_image, "swift_version": "nightly-next", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner }')
+    --argjson env_vars "$windows_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "nightly-next", "image": $container_image, "swift_version": "nightly-next", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars }')
 fi
 
 if [[ "$windows_nightly_main_enabled" == "true" ]]; then
@@ -212,7 +229,8 @@ if [[ "$windows_nightly_main_enabled" == "true" ]]; then
     --arg command_arguments "$windows_nightly_main_command_arguments" \
     --arg container_image "$windows_nightly_main_container_image" \
     --arg runner "$windows_nightly_main_runner" \
-    '.config[.config| length] |= . + { "name": "nightly-main", "image": $container_image, "swift_version": "nightly-main", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner }')
+    --argjson env_vars "$windows_env_vars_json" \
+    '.config[.config| length] |= . + { "name": "nightly-main", "image": $container_image, "swift_version": "nightly-main", "platform": "Windows", "command": $command, "command_arguments": $command_arguments, "setup_command": $setup_command, "runner": $runner, "env": $env_vars }')
 fi
 
 echo "$matrix" | jq -c