remove non-setuptools dependency checks

setup.py

@@ -63,7 +63,7 b' from setupbase import ('
     find_entry_points,
     build_scripts_entrypt,
     find_data_files,
-    check_for_dependencies,
+    check_for_readline,
     git_prebuild,
     check_submodule_status,
     update_submodules,
@@ -78,7 +78,6 b' from setupbase import ('
     install_scripts_for_symlink,
     unsymlink,
 )
-from setupext import setupext
 
 isfile = os.path.isfile
 pjoin = os.path.join
@@ -277,7 +276,7 b' install_requires = ['
 # add platform-specific dependencies
 if sys.platform == 'darwin':
     install_requires.append('appnope')
-    if 'bdist_wheel' in sys.argv[1:] or not setupext.check_for_readline():
+    if 'bdist_wheel' in sys.argv[1:] or not check_for_readline():
         install_requires.append('gnureadline')
 
 if sys.platform.startswith('win'):
@@ -325,13 +324,6 b" if 'setuptools' in sys.modules:"
                                   "ipython_win_post_install.py"}}
 
 else:
-    # If we are installing without setuptools, call this function which will
-    # check for dependencies an inform the user what is needed.  This is
-    # just to make life easy for users.
-    for install_cmd in ('install', 'symlink'):
-        if install_cmd in sys.argv:
-            check_for_dependencies()
-            break
     # scripts has to be a non-empty list, or install_scripts isn't called
     setup_args['scripts'] = [e.split('=')[0].strip() for e in find_entry_points()]
 

setupbase.py

@@ -490,37 +490,23 b' class install_scripts_for_symlink(install_scripts):'
 # Verify all dependencies
 #---------------------------------------------------------------------------
 
-def check_for_dependencies():
-    """Check for IPython's dependencies.
-
-    This function should NOT be called if running under setuptools!
-    """
-    from setupext.setupext import (
-        print_line, print_raw, print_status,
-        check_for_sphinx, check_for_pygments,
-        check_for_nose, check_for_pexpect,
-        check_for_pyzmq, check_for_readline,
-        check_for_jinja2, check_for_tornado
-    )
-    print_line()
-    print_raw("BUILDING IPYTHON")
-    print_status('python', sys.version)
-    print_status('platform', sys.platform)
-    if sys.platform == 'win32':
-        print_status('Windows version', sys.getwindowsversion())
-
-    print_raw("")
-    print_raw("OPTIONAL DEPENDENCIES")
-
-    check_for_sphinx()
-    check_for_pygments()
-    check_for_nose()
-    if os.name == 'posix':
-        check_for_pexpect()
-    check_for_pyzmq()
-    check_for_tornado()
-    check_for_readline()
-    check_for_jinja2()
+def check_for_readline():
+    """Check for GNU readline"""
+    try:
+        import gnureadline as readline
+    except ImportError:
+        pass
+    else:
+        return True
+    try:
+        import readline
+    except ImportError:
+        return False
+    else:
+        if sys.platform == 'darwin' and 'libedit' in readline.__doc__:
+            print("Ignoring readline linked to libedit", file=sys.stderr)
+            return False
+        return True
 
 #---------------------------------------------------------------------------
 # VCS related