diff --git a/common.py b/common.py
index 54fbf6a..b6d3dcc 100644
--- a/common.py
+++ b/common.py
@@ -173,7 +173,7 @@ def mkdir(*names):
 @fill_in_args
 def copy(src, dst):
   debug('copy "%s" to "%s"', topdir(src), topdir(dst))
-  shutil.copy(src, dst)
+  shutil.copy2(src, dst)
 
 
 @fill_in_args
@@ -183,10 +183,11 @@ def copytree(src, dst, **kwargs):
   mkdir(dst)
 
   for name in find(src, **kwargs):
+    target = path.join(dst, path.relpath(name, src))
     if path.isdir(name):
-      mkdir(path.join(dst, path.relpath(name, src)))
+      mkdir(target)
     else:
-      copy(name, path.join(dst, path.relpath(name, src)))
+      copy(name, target)
 
 
 @fill_in_args
@@ -383,12 +384,15 @@ def patch(name, work_dir='{sources}'):
 def configure(name, *confopts, **kwargs):
   info('configuring "%s"', name)
 
+  if 'from_dir' in kwargs:
+    from_dir = kwargs['from_dir']
+  else:
+    from_dir = path.join('{sources}', name)
+
   if kwargs.get('copy_source', False):
     rmtree(path.join('{build}', name))
     copytree(path.join('{sources}', name), path.join('{build}', name))
     from_dir = '.'
-  else:
-    from_dir = path.join('{sources}', name)
 
   with cwd(path.join('{build}', name)):
     remove(find('.', include=['config.cache']))
diff --git a/toolchain-dev b/toolchain-dev
index 4a4e589..72f718c 100755
--- a/toolchain-dev
+++ b/toolchain-dev
@@ -2,8 +2,6 @@
 
 # Build development cross toolchain for m68k-elf target.
 
-from glob import glob
-from logging import info
 from os import environ
 import argparse
 import logging
@@ -98,29 +96,31 @@ def make():
   build('{cloog}')
   install('{cloog}')
 
-  unpack('binutils')
-  configure('binutils',
-            '--prefix={target}',
-            '--target=m68k-elf')
-  build('binutils')
-  install('binutils')
+  with env(CFLAGS='-Wno-error'):
+    configure('binutils',
+              '--prefix={target}',
+              '--with-isl={host}',
+              '--target=m68k-elf',
+              from_dir='{archives}/binutils')
+    build('binutils')
+    install('binutils')
 
-  unpack('gcc')
-  configure('gcc',
-            '--target=m68k-elf',
-            '--with-gmp={host}',
-            '--with-mpfr={host}',
-            '--with-cloog={host}',
-            '--prefix={target}',
-            '--enable-languages=c',
-            '--without-headers')
-  build('gcc', 'all-gcc')
-  install('gcc', 'install-gcc')
+    configure('gcc',
+              '--target=m68k-elf',
+              '--with-gmp={host}',
+              '--with-mpfr={host}',
+              '--with-isl={host}',
+              '--with-cloog={host}',
+              '--prefix={target}',
+              '--enable-languages=c',
+              '--without-headers',
+              from_dir='{archives}/gcc')
+    build('gcc', 'all-gcc')
+    install('gcc', 'install-gcc')
 
 
 def clean():
   rmtree('{stamps}')
-  rmtree('{sources}')
   rmtree('{host}')
   rmtree('{build}')
 
@@ -154,6 +154,7 @@ if __name__ == "__main__":
          build=path.join('{top}', '.build-dev', 'build'),
          sources=path.join('{top}', '.build-dev', 'sources'),
          host=path.join('{top}', '.build-dev', 'host'),
+         tmpdir=path.join('{top}', '.build-dev', 'tmp'),
          target=path.join('{top}', 'm68k-elf'),
          archives=path.join('{top}', '.build-dev', 'archives'))
 
diff --git a/toolchain-m68k b/toolchain-m68k
index 58e8e59..2def19d 100755
--- a/toolchain-m68k
+++ b/toolchain-m68k
@@ -197,8 +197,6 @@ def make():
   environ['CXX'] = ' '.join([find_executable(CXX), '-std=gnu++98', ARCH])
 
   find_executable('patch')
-  find_executable('bison')
-  find_executable('flex')
   find_executable('make')
   find_executable('git')
   find_executable('svn')
diff --git a/toolchain-ppc b/toolchain-ppc
index 835647b..d6e75a8 100755
--- a/toolchain-ppc
+++ b/toolchain-ppc
@@ -70,9 +70,11 @@ def make():
   environ['CC'] = find_executable(cc)
   environ['CXX'] = find_executable(cxx)
 
+  find_executable('patch')
   find_executable('bison')
   find_executable('flex')
   find_executable('make')
+  find_executable('git')
   find_executable('svn')
 
   environ['PATH'] = ":".join([path.join('{target}', 'bin'),
@@ -87,10 +89,11 @@ def make():
         name = path.basename(url)
       fetch(name, url)
 
-  unpack('{lha}', copy=path.join('{build}', '{lha}'))
+  unpack('{lha}')
   configure('{lha}',
             '--disable-shared',
-            '--prefix={host}')
+            '--prefix={host}',
+            copy_source=True)
   build('{lha}')
   install('{lha}')
 
@@ -229,6 +232,7 @@ if __name__ == "__main__":
          build=path.join('{top}', '.build-ppc', 'build'),
          sources=path.join('{top}', '.build-ppc', 'sources'),
          host=path.join('{top}', '.build-ppc', 'host'),
+         tmpdir=path.join('{top}', '.build-ppc', 'tmpdir'),
          target=path.join('{top}', 'ppc-amigaos'),
          archives=path.join('{top}', '.build-ppc', 'archives'))