diff --git a/.gitignore b/.gitignore
index 003d607fd1..e1954660f3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -274,8 +274,9 @@ __pycache__/
 
 .vscode/
 buildtrees/
+build*/
 downloads/
-installed/
+installed*/
 packages/
 scripts/buildsystems/tmp/
 *.exe
diff --git a/scripts/internalCI.ps1 b/scripts/internalCI.ps1
index 16ce4fc7a6..37f4f35a48 100644
--- a/scripts/internalCI.ps1
+++ b/scripts/internalCI.ps1
@@ -1,5 +1,7 @@
 $ErrorActionPreference = "Stop"
 
+rm TEST-internal-ci.xml -errorAction SilentlyContinue
+
 New-Item -type directory downloads -errorAction SilentlyContinue | Out-Null
 ./scripts/bootstrap.ps1
 if (-not $?) { throw $? }
@@ -7,21 +9,14 @@ if (-not $?) { throw $? }
 # Clear out any intermediate files from the previous build
 if (Test-Path buildtrees)
 {
-    Get-ChildItem buildtrees/*/* | ? { $_.Name -ne "src" -and $_.Extension -ne ".log"} | Remove-Item -Recurse -Force
+    Get-ChildItem buildtrees/*/* | ? { $_.Name -ne "src" } | Remove-Item -Recurse -Force
 }
 
 # Purge any outdated packages
 ./vcpkg remove --outdated --recurse
 if (-not $?) { throw $? }
 
-./vcpkg.exe install azure-storage-cpp cpprestsdk:x64-windows-static cpprestsdk:x86-uwp
+./vcpkg.exe install azure-storage-cpp cpprestsdk:x64-windows-static cpprestsdk:x86-uwp `
+bond cryptopp zlib expat sdl2 curl sqlite3 libuv protobuf:x64-windows sfml opencv:x64-windows uwebsockets uwebsockets:x64-windows-static `
+opencv:x86-uwp boost:x86-uwp --keep-going "--x-xunit=TEST-internal-ci.xml"
 if (-not $?) { throw $? }
-
-./vcpkg.exe install bond cryptopp zlib expat sdl2 curl sqlite3 libuv protobuf:x64-windows sfml opencv:x64-windows uwebsockets uwebsockets:x64-windows-static
-if (-not $?) { throw $? }
-
-./vcpkg.exe install opencv:x86-uwp boost:x86-uwp
-if (-not $?) { throw $? }
-
-# ./vcpkg.exe install folly:x64-windows
-# if (-not $?) { throw $? }
diff --git a/toolsrc/include/vcpkg/base/chrono.h b/toolsrc/include/vcpkg/base/chrono.h
index b525852f2f..c791f53fa1 100644
--- a/toolsrc/include/vcpkg/base/chrono.h
+++ b/toolsrc/include/vcpkg/base/chrono.h
@@ -7,18 +7,37 @@ namespace vcpkg::Chrono
 {
     class ElapsedTime
     {
-    public:
-        static ElapsedTime create_started();
+        using duration = std::chrono::high_resolution_clock::time_point::duration;
 
-        constexpr ElapsedTime() : m_start_tick() {}
+    public:
+        constexpr ElapsedTime() : m_duration() {}
+        constexpr ElapsedTime(duration d) : m_duration(d) {}
 
         template<class TimeUnit>
-        TimeUnit elapsed() const
+        TimeUnit as() const
         {
-            return std::chrono::duration_cast<TimeUnit>(std::chrono::high_resolution_clock::now() - this->m_start_tick);
+            return std::chrono::duration_cast<TimeUnit>(m_duration);
         }
 
-        double microseconds() const { return elapsed<std::chrono::duration<double, std::micro>>().count(); }
+        std::string to_string() const;
+
+    private:
+        std::chrono::high_resolution_clock::time_point::duration m_duration;
+    };
+
+    class ElapsedTimer
+    {
+    public:
+        static ElapsedTimer create_started();
+
+        constexpr ElapsedTimer() : m_start_tick() {}
+
+        ElapsedTime elapsed() const
+        {
+            return ElapsedTime(std::chrono::high_resolution_clock::now() - this->m_start_tick);
+        }
+
+        double microseconds() const { return elapsed().as<std::chrono::duration<double, std::micro>>().count(); }
 
         std::string to_string() const;
 
diff --git a/toolsrc/include/vcpkg/globalstate.h b/toolsrc/include/vcpkg/globalstate.h
index 7cea361cf7..40ec7958e8 100644
--- a/toolsrc/include/vcpkg/globalstate.h
+++ b/toolsrc/include/vcpkg/globalstate.h
@@ -9,11 +9,11 @@ namespace vcpkg
 {
     struct GlobalState
     {
-        static Util::LockGuarded<Chrono::ElapsedTime> timer;
+        static Util::LockGuarded<Chrono::ElapsedTimer> timer;
         static std::atomic<bool> debugging;
         static std::atomic<bool> feature_packages;
 
         static std::atomic<int> g_init_console_cp;
         static std::atomic<int> g_init_console_output_cp;
     };
-}
\ No newline at end of file
+}
diff --git a/toolsrc/include/vcpkg/install.h b/toolsrc/include/vcpkg/install.h
index 28896adee8..2e92764dc5 100644
--- a/toolsrc/include/vcpkg/install.h
+++ b/toolsrc/include/vcpkg/install.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <vcpkg/base/chrono.h>
 #include <vcpkg/build.h>
 #include <vcpkg/dependencies.h>
 #include <vcpkg/vcpkgcmdarguments.h>
@@ -25,7 +26,7 @@ namespace vcpkg::Install
 
         PackageSpec spec;
         Build::ExtendedBuildResult build_result;
-        std::string timing;
+        vcpkg::Chrono::ElapsedTime timing;
 
         const Dependencies::AnyAction* action;
     };
@@ -36,6 +37,7 @@ namespace vcpkg::Install
         std::string total_elapsed_time;
 
         void print() const;
+        std::string xunit_results() const;
     };
 
     struct InstallDir
diff --git a/toolsrc/src/vcpkg.cpp b/toolsrc/src/vcpkg.cpp
index 5642f937ce..04d44c414b 100644
--- a/toolsrc/src/vcpkg.cpp
+++ b/toolsrc/src/vcpkg.cpp
@@ -255,7 +255,7 @@ int main(const int argc, const char* const* const argv)
 {
     if (argc == 0) std::abort();
 
-    *GlobalState::timer.lock() = Chrono::ElapsedTime::create_started();
+    *GlobalState::timer.lock() = Chrono::ElapsedTimer::create_started();
 
 #if defined(_WIN32)
     GlobalState::g_init_console_cp = GetConsoleCP();
diff --git a/toolsrc/src/vcpkg/base/chrono.cpp b/toolsrc/src/vcpkg/base/chrono.cpp
index 5d28909fc9..f0e4502312 100644
--- a/toolsrc/src/vcpkg/base/chrono.cpp
+++ b/toolsrc/src/vcpkg/base/chrono.cpp
@@ -50,12 +50,14 @@ namespace vcpkg::Chrono
         return Strings::format("%.4g ns", nanos_as_double);
     }
 
-    ElapsedTime ElapsedTime::create_started()
+    ElapsedTimer ElapsedTimer::create_started()
     {
-        ElapsedTime t;
+        ElapsedTimer t;
         t.m_start_tick = std::chrono::high_resolution_clock::now();
         return t;
     }
 
-    std::string ElapsedTime::to_string() const { return format_time_userfriendly(elapsed<std::chrono::nanoseconds>()); }
+    std::string ElapsedTime::to_string() const { return format_time_userfriendly(as<std::chrono::nanoseconds>()); }
+
+    std::string ElapsedTimer::to_string() const { return elapsed().to_string(); }
 }
diff --git a/toolsrc/src/vcpkg/build.cpp b/toolsrc/src/vcpkg/build.cpp
index 6ef72b639d..b8f122b274 100644
--- a/toolsrc/src/vcpkg/build.cpp
+++ b/toolsrc/src/vcpkg/build.cpp
@@ -67,7 +67,7 @@ namespace vcpkg::Build::Command
         const Build::BuildPackageConfig build_config{
             *scf, spec.triplet(), fs::path{port_dir}, build_package_options, features_as_set};
 
-        const auto build_timer = Chrono::ElapsedTime::create_started();
+        const auto build_timer = Chrono::ElapsedTimer::create_started();
         const auto result = Build::build_package(paths, build_config, status_db);
         System::println("Elapsed time for package %s: %s", spec.to_string(), build_timer.to_string());
 
@@ -323,7 +323,7 @@ namespace vcpkg::Build
         const auto cmd_set_environment = make_build_env_cmd(pre_build_info, toolset);
         const std::string command = Strings::format(R"(%s && %s)", cmd_set_environment, cmd_launch_cmake);
 
-        const auto timer = Chrono::ElapsedTime::create_started();
+        const auto timer = Chrono::ElapsedTimer::create_started();
 
         const int return_code = System::cmd_execute_clean(command);
         const auto buildtimeus = timer.microseconds();
diff --git a/toolsrc/src/vcpkg/commands.ci.cpp b/toolsrc/src/vcpkg/commands.ci.cpp
index 8f79b83e13..f2e984bf89 100644
--- a/toolsrc/src/vcpkg/commands.ci.cpp
+++ b/toolsrc/src/vcpkg/commands.ci.cpp
@@ -63,9 +63,11 @@ namespace vcpkg::Commands::CI
     };
 
     static const std::string OPTION_EXCLUDE = "--exclude";
+    static const std::string OPTION_XUNIT = "--x-xunit";
 
-    static const std::array<CommandSetting, 1> CI_SETTINGS = {{
+    static const std::array<CommandSetting, 2> CI_SETTINGS = {{
         {OPTION_EXCLUDE, "Comma separated list of ports to skip"},
+        {OPTION_XUNIT, "File to output results in XUnit format (internal)"},
     }};
 
     const CommandStructure COMMAND_STRUCTURE = {
@@ -114,6 +116,18 @@ namespace vcpkg::Commands::CI
             result.summary.print();
         }
 
+        auto it_xunit = options.settings.find(OPTION_XUNIT);
+        if (it_xunit != options.settings.end())
+        {
+            std::string xunit_doc = "<assemblies><assembly><collection>\n";
+
+            for (auto&& result : results)
+                xunit_doc += result.summary.xunit_results();
+
+            xunit_doc += "</collection></assembly></assemblies>\n";
+            paths.get_filesystem().write_contents(fs::u8path(it_xunit->second), xunit_doc);
+        }
+
         Checks::exit_success(VCPKG_LINE_INFO);
     }
 }
diff --git a/toolsrc/src/vcpkg/commands.integrate.cpp b/toolsrc/src/vcpkg/commands.integrate.cpp
index f13a999fa6..66c5eb5a91 100644
--- a/toolsrc/src/vcpkg/commands.integrate.cpp
+++ b/toolsrc/src/vcpkg/commands.integrate.cpp
@@ -257,7 +257,7 @@ CMake projects should use: "-DCMAKE_TOOLCHAIN_FILE=%s")",
         std::error_code ec;
         const bool was_deleted = fs.remove(path, ec);
 
-        Checks::check_exit(VCPKG_LINE_INFO, !ec, "Error: Unable to remove user-wide integration: %d", ec.message());
+        Checks::check_exit(VCPKG_LINE_INFO, !ec, "Error: Unable to remove user-wide integration: %s", ec.message());
 
         if (was_deleted)
         {
diff --git a/toolsrc/src/vcpkg/commands.portsdiff.cpp b/toolsrc/src/vcpkg/commands.portsdiff.cpp
index 0277c8bdb1..6752715e4c 100644
--- a/toolsrc/src/vcpkg/commands.portsdiff.cpp
+++ b/toolsrc/src/vcpkg/commands.portsdiff.cpp
@@ -151,14 +151,14 @@ namespace vcpkg::Commands::PortsDiff
         const std::vector<std::string>& added_ports = setp.only_left;
         if (!added_ports.empty())
         {
-            System::println("\nThe following %d ports were added:", added_ports.size());
+            System::println("\nThe following %zd ports were added:", added_ports.size());
             do_print_name_and_version(added_ports, current_names_and_versions);
         }
 
         const std::vector<std::string>& removed_ports = setp.only_right;
         if (!removed_ports.empty())
         {
-            System::println("\nThe following %d ports were removed:", removed_ports.size());
+            System::println("\nThe following %zd ports were removed:", removed_ports.size());
             do_print_name_and_version(removed_ports, previous_names_and_versions);
         }
 
@@ -168,7 +168,7 @@ namespace vcpkg::Commands::PortsDiff
 
         if (!updated_ports.empty())
         {
-            System::println("\nThe following %d ports were updated:", updated_ports.size());
+            System::println("\nThe following %zd ports were updated:", updated_ports.size());
             for (const UpdatedPort& p : updated_ports)
             {
                 System::println("    - %-14s %-16s", p.port, p.version_diff.to_string());
diff --git a/toolsrc/src/vcpkg/globalstate.cpp b/toolsrc/src/vcpkg/globalstate.cpp
index 43230fa4bb..149401b2c1 100644
--- a/toolsrc/src/vcpkg/globalstate.cpp
+++ b/toolsrc/src/vcpkg/globalstate.cpp
@@ -4,7 +4,7 @@
 
 namespace vcpkg
 {
-    Util::LockGuarded<Chrono::ElapsedTime> GlobalState::timer;
+    Util::LockGuarded<Chrono::ElapsedTimer> GlobalState::timer;
     std::atomic<bool> GlobalState::debugging(false);
     std::atomic<bool> GlobalState::feature_packages(false);
 
diff --git a/toolsrc/src/vcpkg/install.cpp b/toolsrc/src/vcpkg/install.cpp
index 0888e21d55..76dc7a527d 100644
--- a/toolsrc/src/vcpkg/install.cpp
+++ b/toolsrc/src/vcpkg/install.cpp
@@ -484,18 +484,18 @@ namespace vcpkg::Install
     {
         std::vector<SpecSummary> results;
 
-        const auto timer = Chrono::ElapsedTime::create_started();
+        const auto timer = Chrono::ElapsedTimer::create_started();
         size_t counter = 0;
         const size_t package_count = action_plan.size();
 
         for (const auto& action : action_plan)
         {
-            const auto build_timer = Chrono::ElapsedTime::create_started();
+            const auto build_timer = Chrono::ElapsedTimer::create_started();
             counter++;
 
             const PackageSpec& spec = action.spec();
             const std::string display_name = spec.to_string();
-            System::println("Starting package %d/%d: %s", counter, package_count, display_name);
+            System::println("Starting package %zd/%zd: %s", counter, package_count, display_name);
 
             results.emplace_back(spec, &action);
 
@@ -521,8 +521,8 @@ namespace vcpkg::Install
                 Checks::unreachable(VCPKG_LINE_INFO);
             }
 
-            results.back().timing = build_timer.to_string();
-            System::println("Elapsed time for package %s: %s", display_name, build_timer.to_string());
+            results.back().timing = build_timer.elapsed();
+            System::println("Elapsed time for package %s: %s", display_name, results.back().timing.to_string());
         }
 
         return InstallSummary{std::move(results), timer.to_string()};
@@ -533,6 +533,7 @@ namespace vcpkg::Install
     static const std::string OPTION_NO_DOWNLOADS = "--no-downloads";
     static const std::string OPTION_RECURSE = "--recurse";
     static const std::string OPTION_KEEP_GOING = "--keep-going";
+    static const std::string OPTION_XUNIT = "--x-xunit";
 
     static const std::array<CommandSwitch, 5> INSTALL_SWITCHES = {{
         {OPTION_DRY_RUN, "Do not actually build or install"},
@@ -541,7 +542,9 @@ namespace vcpkg::Install
         {OPTION_RECURSE, "Allow removal of packages as part of installation"},
         {OPTION_KEEP_GOING, "Continue installing packages on failure"},
     }};
-    static const std::array<std::string, 0> INSTALL_SETTINGS;
+    static const std::array<CommandSetting, 1> INSTALL_SETTINGS = {{
+        {OPTION_XUNIT, "File to output results in XUnit format (Internal use)"},
+    }};
 
     std::vector<std::string> get_all_port_names(const VcpkgPaths& paths)
     {
@@ -555,7 +558,7 @@ namespace vcpkg::Install
         Help::create_example_string("install zlib zlib:x64-windows curl boost"),
         1,
         SIZE_MAX,
-        {INSTALL_SWITCHES, {}},
+        {INSTALL_SWITCHES, INSTALL_SETTINGS},
         &get_all_port_names,
     };
 
@@ -627,7 +630,7 @@ namespace vcpkg::Install
                         library_target_pair.second.erase(library_target_pair.second.begin() + 4,
                                                          library_target_pair.second.end());
                         System::println("    find_package(%s REQUIRED)\n"
-                                        "    # Note: %d targets were omitted\n"
+                                        "    # Note: %zd targets were omitted\n"
                                         "    target_link_libraries(main PRIVATE %s)\n",
                                         library_target_pair.first,
                                         omitted,
@@ -735,6 +738,17 @@ namespace vcpkg::Install
             summary.print();
         }
 
+        auto it_xunit = options.settings.find(OPTION_XUNIT);
+        if (it_xunit != options.settings.end())
+        {
+            std::string xunit_doc = "<assemblies><assembly><collection>\n";
+
+            xunit_doc += summary.xunit_results();
+
+            xunit_doc += "</collection></assembly></assemblies>\n";
+            paths.get_filesystem().write_contents(fs::u8path(it_xunit->second), xunit_doc);
+        }
+
         for (auto&& result : summary.results)
         {
             if (!result.action) continue;
@@ -751,7 +765,7 @@ namespace vcpkg::Install
     }
 
     SpecSummary::SpecSummary(const PackageSpec& spec, const Dependencies::AnyAction* action)
-        : spec(spec), build_result{BuildResult::NULLVALUE, nullptr}, timing("0"), action(action)
+        : spec(spec), build_result{BuildResult::NULLVALUE, nullptr}, action(action)
     {
     }
 
@@ -770,4 +784,41 @@ namespace vcpkg::Install
             }
         return nullptr;
     }
+
+    std::string InstallSummary::xunit_results() const
+    {
+        std::string xunit_doc;
+        for (auto&& result : results)
+        {
+            std::string inner_block;
+            const char* result_string = "";
+            switch (result.build_result.code)
+            {
+                case BuildResult::POST_BUILD_CHECKS_FAILED:
+                case BuildResult::FILE_CONFLICTS:
+                case BuildResult::BUILD_FAILED:
+                    result_string = "Fail";
+                    inner_block = Strings::format("<failure><message><![CDATA[%s]]></message></failure>",
+                                                  to_string(result.build_result.code));
+                    break;
+                case BuildResult::EXCLUDED:
+                case BuildResult::CASCADED_DUE_TO_MISSING_DEPENDENCIES:
+                    result_string = "Skip";
+                    inner_block =
+                        Strings::format("<reason><![CDATA[%s]]></reason>", to_string(result.build_result.code));
+                    break;
+                case BuildResult::SUCCEEDED: result_string = "Pass"; break;
+                default: Checks::exit_fail(VCPKG_LINE_INFO);
+            }
+
+            xunit_doc += Strings::format(R"(<test name="%s" method="%s" time="%lld" result="%s">%s</test>)"
+                                         "\n",
+                                         result.spec,
+                                         result.spec,
+                                         result.timing.as<std::chrono::seconds>().count(),
+                                         result_string,
+                                         inner_block);
+        }
+        return xunit_doc;
+    }
 }
diff --git a/toolsrc/src/vcpkg/postbuildlint.cpp b/toolsrc/src/vcpkg/postbuildlint.cpp
index 0532bce586..2b427737a8 100644
--- a/toolsrc/src/vcpkg/postbuildlint.cpp
+++ b/toolsrc/src/vcpkg/postbuildlint.cpp
@@ -479,7 +479,7 @@ namespace vcpkg::PostBuildLint
         }
 
         System::println(System::Color::warning,
-                        "Mismatching number of debug and release binaries. Found %d for debug but %d for release.",
+                        "Mismatching number of debug and release binaries. Found %zd for debug but %zd for release.",
                         debug_count,
                         release_count);
         System::println("Debug binaries");