diff --git a/third-party/CMakeLists.txt b/third-party/CMakeLists.txt
index 7087ff1..7c5f6c7 100644
--- a/third-party/CMakeLists.txt
+++ b/third-party/CMakeLists.txt
@@ -30,19 +30,24 @@ endif()
 set(ARCHIVE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/${FTDI_ARCHIVE}")
 set(TEMP_DIR "${CMAKE_CURRENT_SOURCE_DIR}/temp_extract")
 
-set(NEED_DOWNLOAD FALSE)
-if(NOT EXISTS "${DEBUG_LIB}" OR NOT EXISTS "${RELEASE_LIB}")
-    set(NEED_DOWNLOAD TRUE)
+set(DOWNLOAD_SUCCESS FALSE)
+
+if(EXISTS "${ARCHIVE_PATH}")
+    execute_process(
+        COMMAND ${CMAKE_COMMAND} -E tar tf "${ARCHIVE_PATH}"
+        RESULT_VARIABLE TAR_RESULT OUTPUT_QUIET ERROR_QUIET)
+    if(TAR_RESULT EQUAL 0)
+        set(DOWNLOAD_SUCCESS TRUE)
+        message(STATUS "FTDI: using existing archive at ${ARCHIVE_PATH}")
+    else()
+        file(REMOVE "${ARCHIVE_PATH}")
+    endif()
 endif()
 
-if(NEED_DOWNLOAD)
+if(NOT DOWNLOAD_SUCCESS)
     set(RETRY_COUNT 0)
-    set(DOWNLOAD_SUCCESS FALSE)
     while(RETRY_COUNT LESS 3)
         math(EXPR RETRY_COUNT "${RETRY_COUNT} + 1")
-        if(EXISTS "${ARCHIVE_PATH}")
-            file(REMOVE "${ARCHIVE_PATH}")
-        endif()
         file(DOWNLOAD "${FTDI_URL}" "${ARCHIVE_PATH}" SHOW_PROGRESS STATUS DOWNLOAD_STATUS TIMEOUT 300)
         list(GET DOWNLOAD_STATUS 0 DOWNLOAD_ERROR_CODE)
         if(DOWNLOAD_ERROR_CODE EQUAL 0 AND EXISTS "${ARCHIVE_PATH}")
@@ -65,63 +70,63 @@ if(NEED_DOWNLOAD)
             "  ${ARCHIVE_PATH}\n"
             "Then re-run cmake.")
     endif()
-    
-    file(REMOVE_RECURSE "${TEMP_DIR}")
-    file(MAKE_DIRECTORY "${TEMP_DIR}")
-    execute_process(COMMAND ${CMAKE_COMMAND} -E tar xzf "${ARCHIVE_PATH}" WORKING_DIRECTORY "${TEMP_DIR}")
-    
-    if(WIN32)
-        file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/lib")
-        file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/lib")
-        file(GLOB SOURCE_LIB "${TEMP_DIR}/${FTDI_ZIP_LIB_GLOB}")
+endif()
 
-        file(GLOB SOURCE_DLL "${TEMP_DIR}/${FTDI_ZIP_DLL_GLOB}")
-        if(SOURCE_DLL)
-            file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin")
-            file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin")
-            file(COPY "${SOURCE_DLL}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin")
-            get_filename_component(SOURCE_DLL_NAME "${SOURCE_DLL}" NAME)
-            if(NOT SOURCE_DLL_NAME STREQUAL "ftd2xx.dll")
-                file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin/${SOURCE_DLL_NAME}" "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin/ftd2xx.dll")
-            endif()
-            file(COPY "${SOURCE_DLL}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin")
-            if(NOT SOURCE_DLL_NAME STREQUAL "ftd2xx.dll")
-                file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin/${SOURCE_DLL_NAME}" "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin/ftd2xx.dll")
-            endif()
-        endif()
+file(REMOVE_RECURSE "${TEMP_DIR}")
+file(MAKE_DIRECTORY "${TEMP_DIR}")
+execute_process(COMMAND ${CMAKE_COMMAND} -E tar xzf "${ARCHIVE_PATH}" WORKING_DIRECTORY "${TEMP_DIR}")
 
-        if(NOT SOURCE_LIB AND FTDI_WIN_ARCH STREQUAL "x64")
-            file(GLOB SOURCE_LIB "${TEMP_DIR}/Static/amd64/ftd2xx.lib")
-        endif()
-        if(NOT SOURCE_LIB)
-            message(FATAL_ERROR
-                "FTDI ${FTDI_WIN_ARCH} lib not found in the downloaded CDM package.\n"
-                "Manually download '${FTDI_ARCHIVE}' from:\n"
-                "  ${FTDI_URL}\n"
-                "Place the downloaded file at:\n"
-                "  ${ARCHIVE_PATH}\n"
-                "Then re-run cmake.")
+if(WIN32)
+    file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/lib")
+    file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/lib")
+    file(GLOB SOURCE_LIB "${TEMP_DIR}/${FTDI_ZIP_LIB_GLOB}")
+
+    file(GLOB SOURCE_DLL "${TEMP_DIR}/${FTDI_ZIP_DLL_GLOB}")
+    if(SOURCE_DLL)
+        file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin")
+        file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin")
+        file(COPY "${SOURCE_DLL}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin")
+        get_filename_component(SOURCE_DLL_NAME "${SOURCE_DLL}" NAME)
+        if(NOT SOURCE_DLL_NAME STREQUAL "ftd2xx.dll")
+            file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin/${SOURCE_DLL_NAME}" "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin/ftd2xx.dll")
         endif()
-        file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/lib")
-        file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/lib")
-        get_filename_component(SOURCE_LIB_NAME "${SOURCE_LIB}" NAME)
-        if(NOT SOURCE_LIB_NAME STREQUAL "ftd2xx.lib")
-            file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/lib/${SOURCE_LIB_NAME}" "${DEBUG_LIB}")
-            file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/lib/${SOURCE_LIB_NAME}" "${RELEASE_LIB}")
+        file(COPY "${SOURCE_DLL}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin")
+        if(NOT SOURCE_DLL_NAME STREQUAL "ftd2xx.dll")
+            file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin/${SOURCE_DLL_NAME}" "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin/ftd2xx.dll")
         endif()
-    else()
-        file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/Linux/Debug/lib")
-        file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/Linux/Release/lib")
-        file(GLOB SOURCE_LIB "${TEMP_DIR}/*/libftd2xx-static.a")
-        file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/Linux/Debug/lib")
-        file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/Linux/Release/lib")
-        file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/Linux/Debug/lib/libftd2xx-static.a" "${DEBUG_LIB}")
-        file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/Linux/Release/lib/libftd2xx-static.a" "${RELEASE_LIB}")
     endif()
-    
-    file(REMOVE_RECURSE "${TEMP_DIR}")
+
+    if(NOT SOURCE_LIB AND FTDI_WIN_ARCH STREQUAL "x64")
+        file(GLOB SOURCE_LIB "${TEMP_DIR}/Static/amd64/ftd2xx.lib")
+    endif()
+    if(NOT SOURCE_LIB)
+        message(FATAL_ERROR
+            "FTDI ${FTDI_WIN_ARCH} lib not found in the downloaded CDM package.\n"
+            "Manually download '${FTDI_ARCHIVE}' from:\n"
+            "  ${FTDI_URL}\n"
+            "Place the downloaded file at:\n"
+            "  ${ARCHIVE_PATH}\n"
+            "Then re-run cmake.")
+    endif()
+    file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/lib")
+    file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/lib")
+    get_filename_component(SOURCE_LIB_NAME "${SOURCE_LIB}" NAME)
+    if(NOT SOURCE_LIB_NAME STREQUAL "ftd2xx.lib")
+        file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/lib/${SOURCE_LIB_NAME}" "${DEBUG_LIB}")
+        file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/lib/${SOURCE_LIB_NAME}" "${RELEASE_LIB}")
+    endif()
+else()
+    file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/Linux/Debug/lib")
+    file(MAKE_DIRECTORY "${CMAKE_SOURCE_DIR}/__Builds/Linux/Release/lib")
+    file(GLOB SOURCE_LIB "${TEMP_DIR}/*/libftd2xx-static.a")
+    file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/Linux/Debug/lib")
+    file(COPY "${SOURCE_LIB}" DESTINATION "${CMAKE_SOURCE_DIR}/__Builds/Linux/Release/lib")
+    file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/Linux/Debug/lib/libftd2xx-static.a" "${DEBUG_LIB}")
+    file(RENAME "${CMAKE_SOURCE_DIR}/__Builds/Linux/Release/lib/libftd2xx-static.a" "${RELEASE_LIB}")
 endif()
 
+file(REMOVE_RECURSE "${TEMP_DIR}")
+
 if(WIN32)
     add_library(ftd2xx_debug STATIC IMPORTED GLOBAL)
     add_library(ftd2xx_release STATIC IMPORTED GLOBAL)
@@ -136,9 +141,9 @@ else()
     )
 endif()
 
-if(WIN32 AND DEFINED ENV{QTDIR})
-    set(QT_BIN_DIR "$ENV{QTDIR}/bin")
-    set(QT_PLUGINS_DIR "$ENV{QTDIR}/plugins")
+if(WIN32 AND DEFINED ENV{QTBIN})
+    set(QT_BIN_DIR "$ENV{QTBIN}")
+    set(QT_PLUGINS_DIR "$ENV{QTBIN}/../plugins")
     set(DEBUG_BIN_DIR "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Debug/bin")
     set(RELEASE_BIN_DIR "${CMAKE_SOURCE_DIR}/__Builds/${FTDI_WIN_ARCH}/Release/bin")