diff --git a/cget/cmake/autotools.cmake b/cget/cmake/autotools.cmake
index 5dc9417..3701785 100644
--- a/cget/cmake/autotools.cmake
+++ b/cget/cmake/autotools.cmake
@@ -103,6 +103,15 @@ macro(preamble PREFIX)
     if(CMAKE_POSITION_INDEPENDENT_CODE AND NOT WIN32)
         set(${PREFIX}_PIC_FLAG "-fPIC")
     endif()
+
+    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    if (APPLE)
+        set(${PREFIX}_C_FLAGS "${${PREFIX}_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_CXX_FLAGS "${${PREFIX}_CXX_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_LINK_FLAGS "${${PREFIX}_LINK_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+    endif (APPLE)
+
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
     if(BUILD_SHARED_LIBS)
         string(APPEND ${PREFIX}_LINK_FLAGS " ${CMAKE_SHARED_LINKER_FLAGS}")
@@ -111,9 +120,6 @@ macro(preamble PREFIX)
     endif()
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
 
-    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-
     foreach(LANG C CXX)
         foreach(DIR ${CMAKE_${LANG}_STANDARD_INCLUDE_DIRECTORIES})
             if(MSVC)
diff --git a/cget/cmake/boost.cmake b/cget/cmake/boost.cmake
index 3f8a49a..87127ec 100644
--- a/cget/cmake/boost.cmake
+++ b/cget/cmake/boost.cmake
@@ -96,6 +96,15 @@ macro(preamble PREFIX)
     if(CMAKE_POSITION_INDEPENDENT_CODE AND NOT WIN32)
         set(${PREFIX}_PIC_FLAG "-fPIC")
     endif()
+
+    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    if (APPLE)
+        set(${PREFIX}_C_FLAGS "${${PREFIX}_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_CXX_FLAGS "${${PREFIX}_CXX_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_LINK_FLAGS "${${PREFIX}_LINK_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+    endif (APPLE)
+
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
     if(BUILD_SHARED_LIBS)
         string(APPEND ${PREFIX}_LINK_FLAGS " ${CMAKE_SHARED_LINKER_FLAGS}")
@@ -104,9 +113,6 @@ macro(preamble PREFIX)
     endif()
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
 
-    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-
     foreach(LANG C CXX)
         foreach(DIR ${CMAKE_${LANG}_STANDARD_INCLUDE_DIRECTORIES})
             if(MSVC)
diff --git a/cget/cmake/make.cmake b/cget/cmake/make.cmake
index 40353aa..7d5f495 100644
--- a/cget/cmake/make.cmake
+++ b/cget/cmake/make.cmake
@@ -101,6 +101,15 @@ macro(preamble PREFIX)
     if(CMAKE_POSITION_INDEPENDENT_CODE AND NOT WIN32)
         set(${PREFIX}_PIC_FLAG "-fPIC")
     endif()
+
+    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    if (APPLE)
+        set(${PREFIX}_C_FLAGS "${${PREFIX}_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_CXX_FLAGS "${${PREFIX}_CXX_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_LINK_FLAGS "${${PREFIX}_LINK_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+    endif (APPLE)
+
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
     if(BUILD_SHARED_LIBS)
         string(APPEND ${PREFIX}_LINK_FLAGS " ${CMAKE_SHARED_LINKER_FLAGS}")
@@ -109,9 +118,6 @@ macro(preamble PREFIX)
     endif()
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
 
-    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-
     foreach(LANG C CXX)
         foreach(DIR ${CMAKE_${LANG}_STANDARD_INCLUDE_DIRECTORIES})
             if(MSVC)
diff --git a/cget/cmake/meson.cmake b/cget/cmake/meson.cmake
index f78c1b7..73e4601 100644
--- a/cget/cmake/meson.cmake
+++ b/cget/cmake/meson.cmake
@@ -130,6 +130,15 @@ macro(preamble PREFIX)
     if(CMAKE_POSITION_INDEPENDENT_CODE AND NOT WIN32)
         set(${PREFIX}_PIC_FLAG "-fPIC")
     endif()
+
+    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    if (APPLE)
+        set(${PREFIX}_C_FLAGS "${${PREFIX}_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_CXX_FLAGS "${${PREFIX}_CXX_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_LINK_FLAGS "${${PREFIX}_LINK_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+    endif (APPLE)
+
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
     if(BUILD_SHARED_LIBS)
         string(APPEND ${PREFIX}_LINK_FLAGS " ${CMAKE_SHARED_LINKER_FLAGS}")
@@ -138,9 +147,6 @@ macro(preamble PREFIX)
     endif()
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
 
-    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-
     foreach(LANG C CXX)
         foreach(DIR ${CMAKE_${LANG}_STANDARD_INCLUDE_DIRECTORIES})
             if(MSVC)
diff --git a/cget/util.py b/cget/util.py
index b2aa1b5..7acf966 100644
--- a/cget/util.py
+++ b/cget/util.py
@@ -1,4 +1,4 @@
-import click, os, sys, shutil, json, six, hashlib, ssl
+import click, os, sys, shutil, json, six, hashlib
 
 if sys.version_info[0] < 3:
     try:
@@ -16,7 +16,7 @@
 else:
     import subprocess
 
-from six.moves.urllib import request
+import requests
 
 def to_bool(value):
     x = str(value).lower()
@@ -205,31 +205,26 @@ def symlink_to(src, dst_dir):
     os.symlink(src, target)
     return target
 
-class CGetURLOpener(request.FancyURLopener):
-    def http_error_default(self, url, fp, errcode, errmsg, headers):
-        if errcode >= 400:
-            raise BuildError("Download failed with error {0} for: {1}".format(errcode, url))
-        return request.FancyURLopener.http_error_default(self, url, fp, errcode, errmsg, headers)
-
 def download_to(url, download_dir, insecure=False):
     name = url.split('/')[-1]
-    file = os.path.join(download_dir, name)
+    file_name = os.path.join(download_dir, name)
     click.echo("Downloading {0}".format(url))
-    bar_len = 1000
-    with click.progressbar(length=bar_len, width=70) as bar:
-        def hook(count, block_size, total_size):
-            percent = int(count*block_size*bar_len/total_size)
-            if percent > 0 and percent < bar_len:
-                # Hack because we can't set the position
-                bar.pos = percent
-                bar.update(0)
-        context = None
-        if insecure: context = ssl._create_unverified_context()
-        CGetURLOpener(context=context).retrieve(url, filename=file, reporthook=hook, data=None)
-        bar.update(bar_len)
-    if not os.path.exists(file):
+    with open(file_name, "wb") as f:
+        response = requests.get(url, stream=True)
+        total_length = response.headers.get('content-length')
+        if total_length is None: # no content length header
+            f.write(response.content)
+        else:
+            total_length = int(total_length)
+            with click.progressbar(length=total_length, width=70) as bar:
+                for data in response.iter_content(chunk_size=4096):
+                    f.write(data)
+                    bar.pos += len(data)
+                    bar.update(0)
+                bar.update(total_length)
+    if not os.path.exists(file_name):
         raise BuildError("Download failed for: {0}".format(url))
-    return file
+    return file_name
 
 def transfer_to(f, dst, copy=False):
     if USE_SYMLINKS and not copy: return symlink_to(f, dst)
diff --git a/requirements.txt b/requirements.txt
index 1df73e3..a8f359b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
 click>=6.6
 # PyYAML
 six>=1.10
+requests>=2.25.1
diff --git a/tools/preamble.cmake b/tools/preamble.cmake
index d95ca55..ae1fed6 100644
--- a/tools/preamble.cmake
+++ b/tools/preamble.cmake
@@ -86,6 +86,15 @@ macro(preamble PREFIX)
     if(CMAKE_POSITION_INDEPENDENT_CODE AND NOT WIN32)
         set(${PREFIX}_PIC_FLAG "-fPIC")
     endif()
+
+    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
+    if (APPLE)
+        set(${PREFIX}_C_FLAGS "${${PREFIX}_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_CXX_FLAGS "${${PREFIX}_CXX_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+        set(${PREFIX}_LINK_FLAGS "${${PREFIX}_LINK_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT}")
+    endif (APPLE)
+
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
     if(BUILD_SHARED_LIBS)
         string(APPEND ${PREFIX}_LINK_FLAGS " ${CMAKE_SHARED_LINKER_FLAGS}")
@@ -94,9 +103,6 @@ macro(preamble PREFIX)
     endif()
     get_property_list(${PREFIX}_LINK_FLAGS LINK_FLAGS)
 
-    set(${PREFIX}_C_FLAGS "${CMAKE_C_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-    set(${PREFIX}_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${${PREFIX}_COMPILE_FLAGS} ${${PREFIX}_PIC_FLAG}")
-
     foreach(LANG C CXX)
         foreach(DIR ${CMAKE_${LANG}_STANDARD_INCLUDE_DIRECTORIES})
             if(MSVC)